Exhibit 99.1 Carlyle Secured Lending III ( CSL III ) Quarterly Update December 31, 2024

Disclaimer and Forward-Looking Statement This presentation (the “Presentation”) has been prepared for former investors in Carlyle Secured Lending III ( CSL III” or the “Company”) to provide them with historical information regarding the performance of the Company during the fourth quarter of 2024. On March 27, 2025, the Company was merged with and into Carlyle Secured Lending, Inc. (“CGBD”). The information contained herein may not be used, reproduced, referenced, quoted, linked by website, or distributed to others, in whole or in part, except as agreed in writing by CGBD, as successor to CSL III. This Presentation does not constitute a prospectus and should under no circumstances be understood as an offer to sell or the solicitation of an offer to buy CGBD common stock or any other securities nor will there be any sale of securities in any state or jurisdiction in which such offer, solicitation or sale would be unlawful prior to the registration or qualification under the securities laws of such state or jurisdiction. This Presentation provides limited information regarding the Company and is not intended to be taken by, and should not be taken by, any individual recipient as investment advice, a recommendation to buy, hold or sell, or an offer to sell or a solicitation of offers to purchase CGBD common stock or any other securities, or as legal, accounting or tax advice. The following slides contain summaries of certain financial and statistical information about the Company. The information contained in this Presentation is summary information that is intended to be considered in the context of the Company’s historical SEC filings and other public announcements. CSL III was managed by CSL III Advisor, LLC (the “Investment Adviser”), an SEC-registered investment adviser and a consolidated subsidiary of The Carlyle Group Inc. (together with its affiliates, “Carlyle”). No Offer or Solicitation This presentation is not, and under no circumstances is it to be construed as, a prospectus or an advertisement and the communication of this presentation is not, and under no circumstances is it to be construed as, an offer to sell or a solicitation of an offer to purchase any securities of CGBD or in any fund or other investment vehicle managed by Carlyle or any of its affiliates. 2

Q4 2024 Executive Summary MARKET BUSINESS PORTFOLIO & INVESTMENT COMMENTARY UPDATES ACTIVITY (2) • Total investments based on fair value were • Carlyle's direct lending platform achieved • Quarterly net total return of 2.1% was approximately $433 million as of record highs for deployment in both the driven by meaningful income generation December 31, 2024 fourth quarter and full year 2024 from the portfolio • CSL III completed the final capital call • Market demand for private credit • Funded approximately $85 million of during the fourth quarter in the amount of remained strong throughout 2024, and has investments in new and existing borrowers $45 million persisted into the beginning of 2025, with during the quarter increased competition for deal flow from • Dividends declared in the fourth quarter • The majority of new originations were in both traditional direct lenders as well as totaled $0.75 per share, inclusive of the first lien assets, as we believe current the broadly syndicated market standard quarterly dividend of $0.57, spreads are compelling for the senior which equates to an annualized net yield • We remain disciplined in the face of this secured credit risk profile (1) of approximately 10.9% ,and a competition, and continue to utilize the • There were approximately $37 million in supplemental dividend of $0.18 breadth and depth of the OneCarlyle repayments during the quarter platform to drive compelling investment • The merger with CGBD was successfully opportunities closed on March 27, 2025. Note: Past performance is not a guarantee or indicator of future results. As of December 31, 2024 unless otherwise stated. These statements reflect the subjective views of Carlyle Direct Lending. 1. Annualized dividend yield is calculated by dividing the declared dividend, excluding the supplemental dividend, by the weighted average of the net asset value at the beginning of the quarter and the capital called during the quarter and annualizing over four periods. There can be no assurance that we will continue to earn income at this rate and our income may decline. 2. Represents the time weighted return for the fourth quarter of 2024. 3

Draft SECTION 01 Portfolio Update

Q4 2024 Quarterly Snapshot Quarterly Activity $45M $85M $269M $292M / 100% (1) (2) (1) CAPITAL CALLED INVESTMENT FUNDINGS NET ASSETS CUMULATIVE CAPITAL CALLED Fund Capital Overview $433M $191M 0.7x $20.76 (3) (4) INVESTMENTS, AT FAIR VALUE TOTAL DEBT OUTSTANDING LEVERAGE RATIO NAV PER SHARE (4) Performance 13.1% 10.9% 2.1% 0.0% (5) Net IRR ANNUALIZED BASE QUARTERLY NET TOTAL ANNUALIZED (6) (7) (8) DIVIDEND YIELD RETURN DEFAULT RATE (1) Capital called in Q4 was due and issued in January 2025; there are no remaining unfunded commitments. (2) Origination activity and resulting capital deployment is dependent on the Investment Adviser’s ability to identify investment opportunities. There can be no guarantee that appropriate opportunities will be identified and if they are, that the Company will be selected to originate any or all such opportunities. Note that figures are based on par/principal value for debt activity and cost/proceeds for equity activity. (3) Past performance is no guarantee of future results. Fair value is determined in good faith by the Investment Advisor pursuant to Rule 2a-5 under the Investment Company Act. Refer to Note 2 and Note 3 to the consolidated financial statements included in our Form 10-Q for the quarter ended September 30, 2024. (4) Values are subject to change over time. (5) Net IRRs are calculated based on the timing of contributions from, and distributions to, the stockholders in the fund after expenses and incentive fees from June 2021 to September 2024. Performance for individual investors may differ depending on subscription date, capital called dates and dividends paid. (6) Dividend paid based on total shares outstanding. The annualized dividend yield is calculated by dividing the declared dividend, excluding the supplemental dividend declared in Q4, by the weighted average net asset value for the quarter and annualizing over 4 periods. There can be no assurance that we will continue to earn income at this rate and our income may decline. (7) Represents the time weighted return for the fourth quarter of 2024. (8) Represents the annualized defaulted invested capital as a percentage of total invested capital since inception. 5

Q4 2024 Quarterly Results • For the year ended December 31, 2024, NAV per share was $20.76 • For the three months ended December 31, 2024, NII per Share was $0.59 and Net Income per Share was $0.53 Summary Balance Sheet Q3 2024 Q4 2024 ASSETS Total investments, at fair value $ 385,594 $ 433,208 Cash, cash equivalents and restricted cash 18,397 30,831 Prepaid expenses and other assets 8,451 9,726 Total Assets $ 412,442 $ 473,765 LIABILITIES & NET ASSETS Debt and secured borrowings $ 151,000 $ 191,000 Other accrued expenses and liabilities 15,979 13,800 Total Liabilities $ 166,979 $ 204,800 Net Assets $ 245,463 $ 268,965 Shares outstanding at end of period 11,709,773 12,958,484 Net Asset Value Per Share $ 20.96 $ 20.76 Summary Income Statement Q4 2024 FY 2024 $ Total Investment Income 13,10 $ 48,654 4 Total Expenses 5,992 22,809 Less waivers and reimbursements of expenses (475) (2,291) Net Investment Income $ 7,587 $ 28,136 Net realized and change in unrealized gains (losses) (792) (2,251) Net Income (Loss) $ 6,795 $ 25,885 Net Investment Income per Share $ 0.59 $ 2.48 Net Income (Loss) per Share $ 0.53 $ 2.28 6

Q4 2024 Portfolio Summary Total investments at Fair Value $433 (4) (4) Floating Rate Senior Secured Exposure Weighted Average Yield on Debt and Income 99% 99% 10.7% (1) Producing Investments at Amortized Cost Number of investments 123 Number of portfolio companies 91 Company EBITDA Sponsored (3) (2) (Median) Average exposure by portfolio company 1.1% 94% $98M (2) Non-accrual investments 0.0% (2) (2) KEY STATISTICS ASSET MIX PORTFOLIO INDUSTRY EXPOSURE Note: 100% of investments are categorized as Level 3 for determination of fair value. (1) Weighted average yields on debt and income producing investments include income producing equity investments. (2) As a percentage of fair value. (3) Excludes forward currency contracts, equity positions, loans on non-accrual, unfunded commitments, and certain asset-backed, asset-based, and recurring revenue loans. (4) As a percentage of fair value of total debt investments. 7

Q4 2024 Portfolio Overview 10 Largest Positions INVESTMENT TYPE COST ($M) FV ($M) % OF FV INDUSTRY First Lien Debt 14.9 15.1 3.5% Consumer Services 1 North Haven Fairway Buyer, LLC 2 Ascend Buyer, LLC First Lien Debt 14.3 14.6 3.4% Containers, Packaging & Glass 3 Avalara, Inc. First Lien Debt 14.0 14.3 3.3% Diversified Financial Services 4 Spotless Brands, LLC First Lien Debt 13.6 13.9 3.2% Consumer Services First Lien Debt 13.6 13.8 3.2% Wholesale 5 Radwell Parent, LLC First Lien Debt 13.5 13.7 3.2% Capital Equipment 6 Dwyer Instruments, Inc. 7 Apex Companies Holdings, LLC First Lien Debt 12.1 12.2 2.8% Environmental Industries 8 First Lien Debt 11.9 12.1 2.8% Diversified Financial Services Accession Risk Management Group, Inc. 9 BlueCat Networks, Inc. (Canada) First Lien Debt 11.8 11.8 2.7% High Tech Industries First Lien Debt 11.3 11.4 2.6% Media: Diversified & Production 10 Park County Holdings, LLC Largest Quarter-over-Quarter MTM Changes TOP CONTRIBUTORS TOP DETRACTORS (1) (1) INVESTMENT TYPE△ ($M) % INVESTMENT TYPE△ ($M) % 1 ADPD Holdings, LLC First Lien Debt 0.2 1.7% 1 Alpine Acquisition Corp II First Lien Debt (0.4) 1.6% 2 Vensure Employer Services, Inc. First Lien Debt 0.1 1.9% 2 BlueCat Networks, Inc. (Canada) First Lien Debt (0.2) 2.7% 3 Azurite Intermediate Holdings, Inc. First Lien Debt 0.1 1.0% 3 Radwell Parent, LLC First Lien Debt (0.1) 3.2% 4 Oranje Holdco, Inc. First Lien Debt 0.1 1.9% 4 Avalara, Inc. First Lien Debt (0.1) 3.3% Accession Risk Management Group, 5 First Lien Debt 0.1 2.8% 5 Excelitas Technologies Corp. First Lien Debt (0.1) 1.7% Inc. (1) Represents each investment’s fair value as a percentage of total investment fair value as of December 31, 2024. 8

Risk Rating Distribution • As of December 31, 2024, two borrowers were on non-accrual status, representing 0.0% of total investments at cost and 0.0% of fair value. PORTFOLIO RISK RATINGS (Dollar amounts in thousands) September 30, 2024 December 31, 2024 Internal Risk Rating Fair Value % of Fair Value Fair Value % of Fair Value 1 $— — % $— — % 2 369,662 96.0 % 417,187 96.6 % 3 15,226 4.0 % 14,564 3.4 % 4 — — % 1 0.0 % 5 2 0.0 % — — % $384,890 100.0 % $431,752 100.0 % Total RATING DEFINITION 1 Borrower is operating above expectations, and the trends and risk factors are generally favorable. Borrower is operating generally as expected or at an acceptable level of performance. The level of risk to our initial cost basis is similar to 2 the risk to our initial cost basis at the time of origination. This is the initial risk rating assigned to all new borrowers. Borrower is operating below expectations and level of risk to our cost basis has increased since the time of origination. The borrower 3 may be out of compliance with debt covenants. Payments are generally current although there may be higher risk of payment default. Borrower is operating materially below expectations and the loan’s risk has increased materially since origination. In addition to the 4 borrower being generally out of compliance with debt covenants, loan payments may be past due, but generally not by more than 120 days. It is anticipated that we may not recoup our initial cost basis and may realize a loss of our initial cost basis upon exit. Borrower is operating substantially below expectations and the loan’s risk has increased substantially since origination. Most or all of the 5 debt covenants are out of compliance and payments are substantially delinquent. It is anticipated that we will not recoup our initial cost basis and may realize a substantial loss of our initial cost basis upon exit. Note: Risk ratings assigned to each debt investment in the portfolio. 9

Net Asset Value Per Share Bridge Q4 2024 Full Year 2024 Note: The net asset value per share and dividends declared per share are based on the shares outstanding at each respective quarter-end. Net investment income per share and net change in realized and unrealized appreciation (depreciation) per share are based on the weighted average number of shares outstanding for the period. The sum of the individual numbers may not add up due to rounding. 10

CSL III Q4 2024 New Investment Activity During Q4 2024, CSL III committed $87.2MM across 10 new platform investments and 10 incremental financings for existing borrowers at a blended weighted average yield of ~9.4% INVESTMENT (1) INVESTMENT TYPE SPREAD OID ALL-IN YIELD AMOUNT ($MM) 1 AMPERSCAP LLC First Lien 4.5 S + 5.25% 2.00% 10.1% 2 Avalara, Inc. (Secondary Purchase) First Lien 0.8 S + 6.25% 0.00% 10.6% 3 BlueCat Networks, Inc. First Lien 2.2 S + 5.75% 1.50% 10.4% 4 Celerion Buyer, Inc. First Lien 1.5 S + 5.00% 1.00% 9.6% 5 Denali Midco 2 LLC (Super Star Car Wash) Second Lien 1.3 S + 5.00% 2.00% 9.8% 6 Galileo Parent, Inc. (Maxar Technologies) First Lien 10.6 S + 5.75% 0.00% 10.1% 7 Generator Buyer, Inc. (TPGS) First Lien 0.8 S + 5.25% 1.75% 10.0% 8 Higginbotham Insurance Agency, Inc. Preferred Equity 0.8 11.00% PIK 1.50% 11.4% 9 IG Investments Holdings, LLC First Lien 1.8 S + 5.00% 0.00% 9.3% 10 Lanes Group First Lien 3.7 SONIA + 7.30% 2.00% 12.7% 11 North Haven Stallone Buyer (Sila) First Lien 5.2 S + 5.25% 1.50% 9.9% 12 Ocorian First Lien 6.9 E + 3.50% + 2.25% PIK 1.50% 6.6% 13 Optimizely North America Inc. First Lien 4.5 S + 5.00% 1.00% 9.6% Pestco, LLC 3.6 S + 5.25% 1.50% 9.9% 14 First Lien Note: Figures are total allocations, including unfunded commitments and equity co-investments. Descriptions of individual investments were selected using objective, non-performance based criteria. These investments do not represent all of the investments purchased, sold or recommended and the reader should not assume that investments identified and discussed were or will be profitable. (1) Yield assumes 4-year average life unless the deal was underwritten to a shorter maturity profile – investment activity includes funded and unfunded commitments. Reference rates reflect quarter-end 3M SOFR of 4.31%, 3M SONIA of 4.85% and 3M EURIBOR of 2.71%. 11

CSL III Q4 2024 New Investment Activity During Q4 2024, CSL III committed $87.2MM across 10 new platform investments and 10 incremental financings for existing borrowers at a blended weighted average yield of ~9.4% INVESTMENT (1) INVESTMENT TYPE CASH SPREAD OID ALL-IN YIELD AMOUNT ($MM) 15 Qnnect, LLC First Lien 0.9 S + 5.25% 1.00% 9.8% 16 QBS Parent Inc. First Lien 9.5 S + 4.75% 0.50% 9.2% 17 Rialto Capital Group Holdings, Inc. First Lien 3.3 S + 5.00% 1.00% 9.6% 18 Rotation Buyer, LLC First Lien 4.9 S + 4.75% 1.00% 9.3% 19 Seahawk Bidco, LLC First Lien 10.5 S + 4.75% 1.00% 9.3% 20 Superstruct First Lien 10 E + 5.50% 1.50% 8.6% Total New Activity: $87.2 9.4% Note: Figures are total allocations, including unfunded commitments and equity co-investments. Descriptions of individual investments were selected using objective, non-performance based criteria. These investments do not represent all of the investments purchased, sold or recommended and the reader should not assume that investments identified and discussed were or will be profitable. (1) Yield assumes 4-year average life unless the deal was underwritten to a shorter maturity profile – investment activity includes funded and unfunded commitments. Reference rates reflect quarter-end 3M SOFR of 4.31%, 3M SONIA of 4.85% and 3M EURIBOR of 2.71%. 12

Draft SECTION 02 Appendix

1 Carlyle Firm Overview Firm Overview 3 4 ​​$192​ bn AUM 190+ investment professionals Global Credit Founded: 1987 AUM: ​​$441​ bn Global ​​$164​ bn AUM 425+ investment professionals Private Equity Employees: ​​2,300​+ 2 Investment Professionals: ​​725​+ ​​$85​ bn AUM 105+ investment professionals Global Investment Solutions Offices / Countries: ​​29​ / 17​ The Carlyle Edge Global Investment Platform “One Carlyle” Global Network ✓ Reach: Deep Industry Knowledge ✓ Expertise: ✓ Impact: Executive Operations Group ✓ Data: Portfolio Intelligence 1) Firm data as of ​​December 31, 2024. 2) Total includes Investment Professionals in the Executive Group. 3) Carlyle Global Credit AUM includes $76.9 billion of insurance related assets. 4) Includes 11 professionals in the Carlyle Global Capital Markets group. Note: AUM numbers may not sum to total due to rounding. Certain communications between Carlyle Global Credit and investment professionals in other business segments may be restricted in accordance with Carlyle's information barrier policy. Past performance is not indicative of future results and there can be no assurance that any trends will continue. 14

Carlyle Global Credit Platform 1 CARLYLE GLOBAL CREDIT – ​​$192​BN AUM LIQUID CREDIT PRIVATE CREDIT REAL ASSETS CREDIT ASSET-BACKED FINANCE AUM: $50.0 billion AUM: $30.4 billion AUM: $19.4 billion AUM: $7.6 billion Directly originated Carlyle managed CLOs Commercial aircraft DIRECT loans, primarily first lien (broadly syndicated leasing / servicing and LENDING and financial sponsor- CLO MANAGEMENT AVIATION FINANCE IG DEBT senior secured bank securitization of aircraft backed loans) portfolios Directly originated, Directly originated privately structured OPPORTUNISTIC private capital solutions asset-backed solutions, CREDIT primarily for non- Credit investments in CLO Equity and debt CLO INFRASTRUCTURE focused on acquiring or sponsored companies U.S. and international NON-IG DEBT INVESTMENT tranches CREDIT lending against infrastructure assets diversified pools of collateral with Flexible mandate across contractual cash flows credit-oriented Senior secured revolving HYBRID CAPITAL solutions, structured LOANS & REVOLVING Lending to global real credit facilities of non-IG REAL ESTATE CREDIT RESIDUAL / EQUITY equity, and stressed / CREDIT estate projects issuers dislocated investments PLATFORM INITIATIVES 1 AUM: $85.0 billion CARLYLE TACTICAL CREDIT FUND CROSS-PLATFORM SMAs ADVISORY CAPITAL Closed-end Interval fund investing dynamically across Carlyle’s Tailored separate accounts investing across the credit platform Credit assets sub-advised for insurance platform entire credit platform Source: The Carlyle Group. As of ​​December 31, 2024 unless otherwise stated. 1) Carlyle Global Credit and Platform Initiatives AUM includes $76.9 billion of insurance related assets. Past performance is not indicative of future results and there can be no assurance that any trends will continue. 15

Carlyle Direct Lending Investment Philosophy & Overview Carlyle Direct Lending seeks to operate in the middle market, utilizing an integrated platform sourcing approach Note: Comments made here are based on Carlyle's subjective views. Past performance is not indicative of future results. There can be no assurance that a fund will be able to achieve comparable results, implement its investment strategy or achieve its investment objective. No assurance is given that any trends will continue, that forecasts will ultimately materialize, or that investment opportunities will be available. 16