Athanasios “Thanasi” Kokkinakis /θəˈnɑːsi ˌkɒkɪˈnɑːkɪs/ (Greek: Αθανάσιος “Θανάσης” Κοκκινάκης (Thanasis); born 10 April 1996) is an Australian professional tennis player. He has been ranked as high as world No. 69 in singles by the Association of Tennis Professionals (ATP), which he first achieved in June 2015. He has won one ATP Tour title in doubles and produced his best Grand Slam singles performance at the 2015 French Open after reaching the third round, where he lost to eventual runner-up Novak Djokovic. Kokkinakis also has a career-high doubles ranking of world No. 137, which he attained in July 2015. As a junior, Kokkinakis was ranked as high as No. 10 in the world. He won one junior Grand Slam title, the doubles title at the 2013 Wimbledon Championships with partner Nick Kyrgios, and was the runner-up in two additional junior Grand Slam singles finals that same year. As a professional, Kokkinakis broke into the top 100 for the first time in 2015, during which he won one title on the ATP Challenger Tour and made the fourth round of an ATP Masters 1000 tournament for the first time at the 2015 Indian Wells Masters. After an injury-plagued 2016, he reached his first ATP Tour finals the next year, when he won the 2017 Brisbane International doubles title with Jordan Thompson but lost at the 2017 Los Cabos Open in singles to Sam Querrey. In 2018, Kokkinakis won two additional Challenger titles and ended the year having re-entered the top 150. However, over the next two years, further injuries prevented him from regularly competing on the professional circuit, but he made his return in 2021 and he reached two Challenger finals, of which he won one. He continued his comeback in 2022 and appeared in his first ATP Tour semifinal since 2017 at the 2022 Adelaide International 1.