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: March 6, 2014

(Date of earliest event reported)

Stillwater Mining Company

(Exact name of registrant as specified in its charter)

(406) 373-8700

(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:

Item 5.02. Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers

On December 3, 2013, Stillwater Mining Company (the “Company”) entered into executive employment agreements with each of Kristen K. Koss, Vice President, Human Resources and Safety, Kevin G. Shiell, Vice President of Mining Operations, and Brent R. Wadman, Vice President of Legal Affairs and Corporate Secretary. The following summaries do not purport to be complete descriptions of the terms and conditions of each agreement, and are qualified in their entirety by reference to the text of each agreement, which are attached as exhibits hereto.

Kristen K. Koss Executive Employment Agreement

Term: The agreement provides for an initial term continuing through March 6, 2015. The agreement may be renewed for successive one-year terms upon written agreement of both parties no later than 30 days prior to the end of the then current term.

Base Salary: Ms. Koss shall receive an initial base salary of $225,000 per year, subject to periodic review and adjustment; provided, however, such base salary may not be reduced except in connection with an across-the-board reduction of the salaries of all named executive officers of the Company.

Short Term Incentive Program: Ms. Koss shall participate in the Company’s Short-Term Incentive Program (“STIP”) as follows:

Long Term Incentive Program: Ms. Koss shall participate in the Company’s Long Term Incentive Plan (“LTIP”) as follows:

Additional Benefits: During the term of the Agreement, Ms. Koss shall be entitled to participate in all health insurance, pension, retirement, profit-sharing or other benefit plans adopted by the Company for its senior management, and may take up to six weeks of paid vacation per year.

Compensation upon Termination: Upon termination of Ms. Koss’s employment during the term of the agreement, Ms. Koss shall be entitled to the following:

Restrictive Covenants: For two years following the termination of Ms. Koss’s employment with the Company for any reason, the agreement provides that, if Ms. Koss owns, operates, manages, controls, participates in, is employed by, performs any services for or otherwise assists any enterprise or venture that directly competes with the Company, then Ms. Koss must pay to the Company 100% of all gross revenue earned by such enterprise or venture from any customers who were customers of the Company on the date of Ms. Koss’s termination or at any time during the thirty-day period immediately preceding such termination date. In addition, for two years following termination of employment with the Company, Ms. Koss may not, without the consent of the Company, directly or indirectly solicit the employment or retaining of any employees or consultants of the Company or its affiliates.

Kevin G. Shiell Executive Employment Agreement

Except for the following, the provisions of Mr. Shiell’s executive employment agreement are materially the same as those found in Ms. Koss’s executive employment agreement.

Base Salary: Mr. Shiell shall receive an initial base salary of $310,000 per year, subject to periodic review and adjustment; provided, however, such base salary may not be reduced except in connection with an across-the-board reduction of the salaries of all named executive officers of the Company.

Short Term Incentive Program: Mr. Shiell shall participate in the Company’s STIP as follows:

Long Term Incentive Program: Mr. Shiell shall participate in the Company’s LTIP as follows:

Brent R. Wadman Executive Employment Agreement

The provisions of Mr. Wadman’s executive employment agreement are materially the same as those found in Ms. Koss’s executive employment agreement, including in respect of base salary and percentage participation in the Company’s STIP and LTIP.

Item 9.01. Financial Statements and Exhibits

SIGNATURE

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

Exhibit Index