Reilly Opelka (born August 28, 1997) is an American tennis player. At 6 feet 11 inches tall, he is the joint-tallest ATP-ranked player ever, along with Ivo Karlović, and can serve in the low-140 mph range. He is a Junior Wimbledon champion and Redbull ambassador. He has won two ATP singles titles and reached his career-high ranking of No. 31 in October 2019.
Opelka moved from Michigan to Palm Coast, Florida at age 4. He didn't start playing tennis regularly until he began training through USTA in Boca Raton at 12 years old. He credits Tom Gullikson, whom his father knew from playing golf, for much of his early development as a tennis player. Opelka is close friends with Taylor Fritz and was the best man at Fritz's wedding. His uncle is radio talk show host Mike Opelka.
Opelka made his ATP debut at the 2016 U.S. Men's Clay Court Championship, where he lost in the first round to fifth seed Sam Querrey. In August, Opelka won his first three career ATP matches at the BB&T Atlanta Open to reach the semi-finals at just his 3rd career ATP event. This included a victory over 203 cm player No. 27 Kevin Anderson in which he saved two match points on Anderson's serve. He lost in the semi-finals to top seed John Isner. He continued his momentum with first round wins at the Los Cabos Open and the Cincinnati Masters where he defeated Sergiy Stakhovsky and Jérémy Chardy respectively to move into the Top 300 of the ATP rankings. After struggling with a foot injury towards the end of the summer, Opelka returned to the USTA Pro Circuit for the indoor season and won his first ATP Challenger title in Charlottesville to finish the year just outside the Top 200.
On the ATP world Tour, he reached the quarterfinals at the Delray Beach Open, picking up his first top 10 win of his burgeoning career, defeating world No. 8 Jack Sock in the second round over three sets.
His solid performance at the ATP Challenger Tour earned him first career Top 100 year end finish in singles, ending the season at 99.
At the Australian Open, Opelka created a huge upset when he defeated compatriot John Isner in the first round. This was the second top 10 win of his career. In February, Opelka again knocked off John Isner on the way to his first ATP title, the New York Open. At Wimbledon, in July, he achieved his best Grand Slam result to date, making it to the tournament's third round and knocking out Stan Wawrinka in the process. Over the summer and fall, he reached the semifinals of tournaments in Atlanta, Tokyo, and Basel solidifying his standing amongst the best tennis players in the world. In November, he participated in the Davis Cup Finals for the United States, ultimately losing both his rubbers. He finished the season ranked 36th in the world.