Dennis Novak (; born 28 August 1993, in Wiener Neustadt) is an Austrian former professional tennis player. Novak achieved a career-high ATP singles ranking of world No. 85 in March 2020.
Novak made his ATP main draw debut at the 2013 Bet-at-home Cup Kitzbühel where he defeated Matthias Haim, Lorenzo Giustino and Tihomir Grozdanov in the qualifying rounds. In the main draw, Novak lost to compatriot Andreas Haider-Maurer.
In 2018, Novak reached the third round of a major for the first time at the 2018 Wimbledon Championships, but lost to Milos Raonic.
In April 2019, he won his first ATP Challenger Tour title in Taipei. In November, he won his second at the 2019 Slovak Open.
He made his debut in the top 100 on 13 January 2020 at world No. 99 and reached a career high ranking of No. 85 on 2 March 2020.
He reached the second round at the 2022 Wimbledon Championships for a second time with a win over Facundo Bagnis. He became Austrian No. 1 on 15 August 2022 ranked at No. 133.
He qualified for the 2023 Wimbledon Championships for a third consecutive year but lost again to Milos Raonic.
He fell out of the top 200 at world No. 213 on 15 January 2024 and finished the 2024 season ranked No. 352 on 2 December 2024.
Novak announced his retirement from professional tennis in November 2025.
Current through the 2022 Davis Cup.
Novak's match record against those who have been ranked in the Top 10, with those who have been No. 1 in boldface.