Exhibit 23

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

We hereby consent to the incorporation by reference in the Registration Statements on Form S-3 (No. 333-221763) and Form S‑8 (No. 333-223143, No. 333-220078, No.333-188693, No.333-168444, No. 333-168443, No. 333-146176, No. 333-130001, No. 333-152903, No. 333-123778, No. 333-75531, No. 333-57006, No. 333-57008, No. 333-57010, and No. 333-161307) of Varian Medical Systems, Inc. of our report dated November 26, 2018 relating to the consolidated financial statements, financial statement schedule and the effectiveness of internal control over financial reporting, which appears in this Form 10-K.

/s/ PricewaterhouseCoopers LLP

San Jose, California

November 26, 2018

PricewaterhouseCoopers LLP, 488 Almaden Boulevard, Suite 1800, San Jose, CA 95110

T: (408) 817 3700, F: (408) 817 5050, www.pwc.com/us