UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d)

of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): March 2, 2015

Oaktree Capital Group, LLC

(Exact name of registrant as specified in its charter)

(213) 830-6300

(Registrant’s telephone number, including area code)

Not Applicable

(Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

On March 2, 2015, Oaktree Capital Group, LLC (the “Company”) entered into an underwriting agreement (the “Underwriting Agreement”) with Morgan Stanley & Co. LLC (the “Underwriter”), to issue and sell to the Underwriter (the “Offering”) 4,000,000 Class A units representing limited liability company interests of the Company (the “Class A units”) and, at the option of the Underwriter, up to an additional 600,000 Class A units at a price of $51.70 per Class A unit, resulting in $206.8 million in proceeds to the Company net of underwriting commissions and discounts (or $237.8 million if the Underwriter exercises in full its option to purchase additional Class A units). The Company intends to use the net proceeds from the Offering to acquire interests in its business from certain of its directors, current and former employees and other investors, including certain senior executives and other members of its senior management. Accordingly, the Company will not retain any proceeds from the sale of Class A units in the Offering.

The Offering is being made pursuant to the Company’s effective shelf registration statement on Form S-3 (File No. 333-188596) and a related prospectus, filed with the Securities and Exchange Commission (the “SEC”) on May 14, 2013, and the related prospectus supplement, filed with the SEC on March 4, 2015.

We have agreed to indemnify the Underwriter against certain liabilities or to contribute to payments the Underwriter may be required to make because of any of those liabilities. In addition, we have agreed to reimburse the Underwriter for certain FINRA and Blue Sky expenses in an amount up to $5,000.

The Underwriter and its affiliates are full service financial institutions engaged in various activities, which may include securities trading, commercial and investment banking, financial advisory, investment management, investment research, principal investment, hedging, financing and brokerage activities. The Underwriter and its affiliates have, from time to time, performed, and may in the future perform, various financial advisory and investment banking services for the Company, for which they received or will receive customary fees and reimbursement of expenses. In particular, an affiliate of Morgan Stanley & Co. LLC is a lender under certain of the Company’s existing credit facilities described under “Future Sources and Uses of Liquidity” in its Annual Report on Form 10-K for the year ended December 31, 2014, filed with the SEC on February 27, 2015.

The foregoing description is a summary and is qualified in its entirety by reference to the complete text of the Underwriting Agreement filed as Exhibit 1.1 hereto and incorporated herein by reference.

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, as amended, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.