EXHIBIT 23.1

Deloitte & Touche LLP

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McLean, VA 22102

USA

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CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

We consent to the incorporation by reference in Registration Statement Nos. 333-138095, 333-153360 and 333-169693 on Form S-8 and Post-Effective Amendment No. 1 to Registration Statement No. 333-138095 on Form S-8 of our reports dated March 25, 2015, relating to the consolidated financial statements of Leidos Holdings, Inc. and subsidiaries and the effectiveness of Leidos Holdings, Inc. and subsidiaries’ internal control over financial reporting, appearing in this Annual Report on Form 10-K of Leidos Holdings, Inc. for the year ended January 30, 2015.

/s/ Deloitte & Touche LLP

McLean, Virginia March 25, 2015

Member of

Deloitte Touche Tohmatsu