Exhibit 23.1
CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM
We have issued our report dated June 26, 2018, with respect to the financial statements and supplemental schedule included in the Annual Report of Orbital ATK, Inc. 401(k) Plan on Form 11-K for the year ended December 31, 2016. We hereby consent to the incorporation by reference of said report in the Registration Statement of Orbital ATK, Inc. on Form S-8 (File No. 333-148502).
| /s/ Grant Thornton LLP |
| Minneapolis, Minnesota |
| June 26, 2018 |