The 2019 ATP Finals was a men's tennis tournament played at the O2 Arena on indoor hard courts in London, United Kingdom, from 10 to 17 November 2019. It was the season-ending event for the 8 highest-ranked singles players on the 2019 ATP Tour and was the 50th edition of the tournament. The singles event was won by Stefanos Tsitsipas over Dominic Thiem in three sets