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 10, 2017

Swift Transportation Company

(Exact Name of Registrant as Specified in Charter)

Delaware

(State or Other Jurisdiction of Incorporation)

2200 South 75th Avenue

Phoenix, Arizona 85043

(Address of Principal Executive Offices) (Zip Code)

(602) 269-9700

(Registrant’s telephone number, including area code)

N/A

(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 April 10, 2017, Swift Transportation Company (the “Company”) issued a press release revising its previously provided earnings guidance for the quarter ending March 31, 2017.

A copy of the press release is attached hereto as Exhibit 99. The information contained herein and in the accompanying Exhibit shall not be incorporated by reference into any filing of the Company, whether made before or after the date hereof, regardless of any general incorporation language in such filing, unless expressly incorporated by specific reference to such filing. The information furnished in this report on Form 8-K, including Exhibit 99, shall be deemed to be “furnished” and therefore shall not be deemed to be “filed” for the purposes of Section 18 of the Securities Exchange Act of 1934, or otherwise subject to the liabilities of that section or Sections 11 and 12(a)(2) of the Securities Act of 1933, as amended. This information will not be deemed an admission as to the materiality of any information contained herein that is required to be disclosed solely by regulation FD.

Forward-Looking Statements

This communication contain statements that may constitute forward-looking statements, which are based on information currently available, usually defined by words such as “anticipates,” “believes,” “estimates,” “plans,” “projects,” “expects,” “hopes,” “intends,” “will,” “could,” “should,” “may,” or similar expressions which speak only as of the date the statement was made. Such forward-looking statements are made pursuant to the safe harbor provisions of the Private Securities Litigation Reform Act of 1995. Such statements include, but are not limited to, statements concerning:

Such forward-looking statements are inherently uncertain, and are based upon the current beliefs, assumptions and expectations of Company management and current market conditions, which are subject to significant risks and uncertainties, as set forth in the Risk Factors section of our Annual Report on Form 10-K for the year ended December 31, 2016. As to the Company’s business and financial performance, the following factors, among others, could cause actual results to materially differ from those in forward-looking statements:

Important factors, in addition to those listed above and in our filings with the SEC, could impact us financially. As a result of these and other factors, actual results may differ from those set forth in the forward-looking statements, and the prices of the Company’s securities may dramatically fluctuate. The Company makes no commitment, and disclaims any duty, to update or revise any forward-looking statements to reflect future events, new information or changes in these expectations, except as required by law.

SIGNATURES

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.

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