Denis Zivkovic (born September 30, 1987) is an American professional tennis player and competes mainly on the ATP Challenger Tour and ITF Futures, both in singles and doubles. Denis was sponsored by several prominent tennis and sports brands, amongst which, Loriet Sports, a super-premium American activewear brand. Zivkovic reached his highest ATP singles ranking, No. 292 on March 18, 2013, and his highest ATP doubles ranking, No. 161, on August 5, 2013.