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): April 19, 2016

NAVISTAR INTERNATIONAL CORPORATION

(Exact name of registrant as specified in its charter)

Registrant’s telephone number, including area code (331) 332-5000

(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:

Clarke Amended and Restated Employment Agreement

On April 22, 2016, Navistar International Corporation (the “Company”) entered into an Amended and Restated Employment and Services Agreement (the “Agreement”) with the Company’s President and Chief Executive Officer, Troy A. Clarke. The Agreement replaces Mr. Clarke’s Employment and Services Agreement with the Company dated April 22, 2013, which expired on April 14, 2016. The following is a description of the material terms of the Agreement, which description is qualified by reference to a copy of the Agreement attached as Exhibit 10.1 to this Current Report on Form 8-K.

Term of Employment. The employment of Mr. Clarke under the Agreement commenced on April 22, 2016 (the “Effective Date”) and will end on the second anniversary of the Effective Date, unless it is terminated earlier by the Company or by Mr. Clarke, as more fully described below (the “Service Term”).

Duties and Scope of Employment. Under the terms of the Agreement, Mr. Clarke will continue to serve as Chief Executive Officer and President of the Company, reporting exclusively to the Company’s Board of Directors (“Board”), and will have the status of the highest ranking executive officer of the Company. In addition, the Company will continue to nominate Mr. Clarke as a candidate for election as a director by the stockholders at each annual meeting held during the Service Term. During the Service Term, Mr. Clarke has agreed not to engage, without prior approval of the Non-Executive Chairman of the Board (or, if there is no Non-Executive Chairman of the Board, the Lead Director), in any other employment, occupation or consulting activity, except that, without such approval, Mr. Clarke may serve in any capacity with any civic, educational or charitable organization, participate in industry affairs and manage his and his family’s personal passive investments, provided that such services do not materially interfere with his obligations to the Company.

Compensation. Mr. Clarke’s compensation under the Agreement consists of the following:

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Termination and Severance. Mr. Clarke’s employment and service relationship with the Company may be terminated at any time: (i) by the Company with or without Cause (as defined by the Agreement), or (ii) by Mr. Clarke due to Constructive Termination (as defined by the Agreement), in either case in accordance with the procedures set forth in the Agreement.

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Limitation on Payments. If any payment or benefit received or to be received by Mr. Clarke under the Agreement or under any other plan, arrangement or agreement, including payment or benefit received in connection with a Change in Control or a termination of employment (collectively, the “Total Payments”) would be subject to the excise tax imposed under Section 4999 of the Internal Revenue Code of 1986, as amended (the “Excise Tax”), then the payments to which Mr. Clarke otherwise is entitled will be reduced to the extent necessary so that no portion of the Total Payments will be subject to the Excise Tax, but only if the net after-tax amount of such Total Payments, as so reduced, is greater than or equal to the net after-tax (including the excise tax) amount of such Total Payments without such reduction.

Restrictive Covenants. The Agreement contains covenants of Mr. Clarke with regard to the non-disclosure of confidentiality information while employed and for an unlimited period thereafter, and with regard to non-disparagement, non-competition, non-solicitation and cooperation while employed and for a period of twenty-four months following a termination.

Indemnification. Under the Agreement, Mr. Clarke will be provided indemnification to the maximum extent permitted by the Company’s Certificate of Incorporation and Bylaws, subject to applicable law, including coverage, if applicable, under any directors and officers insurance policies maintained by the Company.

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The following documents are filed herewith:

Forward Looking Statements

Information provided and statements contained in this report that are not purely historical are forward-looking statements within the meaning of the federal securities laws. Such forward-looking statements only speak as of the date of this report and the Company assumes no obligation to update the information included in this report. Such forward-looking statements include information concerning our possible or assumed future results of operations, including descriptions of our business strategy. These statements often include words such as “believe,” “expect,” “anticipate,” “intend,” “plan,” “estimate,” or similar expressions. These statements are not guarantees of performance or results and they involve risks, uncertainties, and assumptions. For a further description of these factors, see the risk factors set forth in our filings with the Securities and Exchange Commission, including our annual report on Form 10-K for the fiscal year ended October 31, 2015. Although we believe that these forward-looking statements are based on reasonable assumptions, there are many factors that could affect our actual financial results or results of operations and could cause actual results to differ materially from those in the forward-looking statements. All future written and oral forward-looking statements by us or persons acting on our behalf are expressly qualified in their entirety by the cautionary statements contained or referred to above. Except for our ongoing obligations to disclose material information as required by the federal securities laws, we do not have any obligations or intention to release publicly any revisions to any forward-looking statements to reflect events or circumstances in the future or to reflect the occurrence of unanticipated events.

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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.

Dated: April 22, 2016

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EXHIBIT INDEX

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