Jan-Lennard Struff (; born 25 April 1990) is a German professional tennis player. He has a career-high ATP singles ranking of world No. 21, achieved on 19 June 2023. He also reached a best doubles ranking of No. 21 on 22 October 2018. He is currently the No. 3 German singles player.
Struff became the third oldest first-time ATP champion (since the inception of the ATP Tour in 1990) in 2024 at the age of 33, when he won his first ATP singles title by beating third seeded Taylor Fritz in straight sets in the final of the BMW Open.
Career 2014: First two ATP semifinals, top 50 debut Struff advanced to his first semifinals on the ATP Tour in Marseille, Munich and Metz. He entered the top 50 in the ATP rankings for the first time in his career and finished the year in the top 100 also for the first time at World No. 59.
2015: Davis Cup debut Struff made his Davis Cup debut for Germany against France in the first round. He lost the first rubber to Gilles Simon with 8–10 in the fifth set, and his team lost the tie with 2–3.
2016: First ATP 1000 third round, top-3 win Struff reached the third round of the Paris Masters as a qualifier, his best showing at the Masters 1000 level thus far, after beating world No. 3 Stan Wawrinka, saving a match point.
2017: Two ATP semifinals Struff reached the semifinals of both Winston-Salem and St. Petersburg.
2018: Australian Open doubles semifinal, first doubles title Struff got to the semifinals in the Australian Open men's doubles in partnership with Ben McLachlan, including a win over the No. 1 seeds Łukasz Kubot and Marcelo Melo.
At the 2018 Wimbledon Championships, he reached the quarterfinals in doubles, also partnering with McLachlan, where they lost to the wildcard pair of Frederik Nielsen and Joe Salisbury.
In Tokyo, Struff defeated Marin Čilić and had a match point in the second set of his quarterfinal encounter against Denis Shapovalov. At the same tournament, he won the first title of his career in doubles, partnering again with McLachlan.
2019: Top-3 win, French Open fourth round
Struff started his 2019 season at the Brisbane International. He lost in the first round to Jérémy Chardy. At the ASB Classic in Auckland, he upset fourth seed and world No. 24, Pablo Carreño Busta, in the quarterfinals. He was defeated in the semifinals by British wildcard Cameron Norrie. However, in doubles, he and his partner, Ben McLachlan, won the title, beating Raven Klaasen and Michael Venus in the final. Ranked 51 at the Australian Open, he lost in the first round to Australian Matthew Ebden in four sets.
In February, Struff competed at the Sofia Open. He lost in the second round to second seed and world No. 12, Stefanos Tsitsipas. In Rotterdam, he fell in the first round of qualifying to Dutch wildcard Ryan Nijboer. At the Dubai Championships, he stunned seventh seed and world No. 14, Milos Raonic, in the first round. He was defeated in the second round by Márton Fucsovics. In doubles, he and Ben McLachlan reached the final where they lost to Joe Salisbury and Rajeev Ram. At the Indian Wells Masters, he upset world No. 3 and compatriot, Alexander Zverev, in the third round. He was eliminated from the tournament in the fourth round by 13th seed and world No. 14, Milos Raonic. In Miami, he lost in the first round to American qualifier Reilly Opelka.
Struff started his clay-court season at the Monte-Carlo Masters. He upset 15th seed and world No. 20, Denis Shapovalov, in the first round. He lost in the second round to Grigor Dimitrov. In Barcelona, he beat 10th seed and world No. 22, David Goffin, in the second round. He upset fifth seed and world No. 8, Stefanos Tsitsipas, in the third round for his second Top 10 win of the season. He was defeated in his quarterfinal match by top seed, world No. 2, and eleven-time champion, Rafael Nadal. At the BMW Open in Munich, he lost in the first round to Brazilian qualifier Thiago Monteiro. In Madrid, he was defeated in the second round by ninth seed Marin Čilić. At the Italian Open, he upset ninth seed and world No. 10, Marin Čilić, in the second round. He was eliminated in the third round by world No. 6 Kei Nishikori. Ranked 45 at the French Open, he upset 20th seed and world No. 24, Denis Shapovalov, in the first round. In the third round, he upset 13th seed and world No. 15, Borna Ćorić, in a third round thriller which lasted four-hour-22-minutes. With his third round victory over Ćorić, he reached the fourth round for the first time. He fell in his fourth-round match to world No. 1, Novak Djokovic.
Struff started his grass-court season at the Stuttgart Open. He beat eighth seed and world No. 25, Denis Shapovalov, in the first round. He reached the semifinals where he lost to Matteo Berrettini. In Halle, he was defeated in the second round by third seed and world No. 9, Karen Khachanov. Seeded 33rd at Wimbledon, he made it to the third round, where he lost to Mikhail Kukushkin.
Seeded seventh at the Hamburg Open, Struff lost in the second round to Pablo Carreño Busta.
Seeded 14th at the Citi Open, Struff lost in the second round to Jordan Thompson. At the Rogers Cup in Montreal, he was defeated in the second round by 13th seed and world No. 17, Nikoloz Basilashvili. In Cincinnati, he stunned fifth seed and world No. 7, Stefanos Tsitsipas, in the second round in a tight three-set match. He lost in the third round to ninth seed and world No. 8, and eventual champion, Daniil Medvedev. Ranked 37 at the US Open, he was beaten in the second round by world No. 14 John Isner.
Seeded eighth at the Moselle Open, Struff lost in the first round to Pierre-Hugues Herbert. In Tokyo, he was defeated in the first round by Japanese wildcard Go Soeda. At the Shanghai Masters, he was eliminated from the tournament in the first round by 11th seed and world No. 13, Matteo Berrettini. Seeded seventh at the European Open, he lost in the second round to Frances Tiafoe. At the Swiss Indoors, he reached the quarterfinals where he was defeated by eventual finalist Alex de Minaur. At the Paris Masters, he upset world No. 8 and defending champion, Karen Khachanov, in the second round for the seventh Top 10 win of his career. He lost in the third round to Jo-Wilfried Tsonga in three sets.
2020: Top 30 debut Struff started his 2020 season by representing Germany at the 1st edition of the ATP Cup. Germany was in Group F alongside Australia, Greece, and Canada. Against Australia, he lost to Nick Kyrgios. Against Greece, he won his match over Michail Pervolarakis. Against Canada, he got the victory over Félix Auger-Aliassime. In the end, Germany ended 3rd in Group F. Seeded seventh at the first edition of the Adelaide International, he lost in the second round to Australian wildcard Alex Bolt. Ranked 37 at the Australian Open, he was defeated in the first round by world No. 2, seven-time champion, and eventual champion, Novak Djokovic, in four sets.
At the Rotterdam Open, Struff lost in the first round to eventual finalist, Félix Auger-Aliassime, in three sets. However, in doubles, he and his partner, Henri Kontinen, reached the final where they lost to Pierre-Hugues Herbert and Nicolas Mahut. In Dubai, he upset fifth seed, world No. 12, and 2018 champion, Roberto Bautista Agut, in the first round. He reached the quarterfinals where he fell to second seed, world No. 6, last year finalist, and eventual finalist, Stefanos Tsitsipas, in three sets. Representing Germany in the Davis Cup tie against Belarus, he won both of his rubbers by beating Ilya Ivashka and Egor Gerasimov. Germany ended up winning the tie over Belarus 4-1. The ATP Tour cancelled all tournaments from March through July due to the COVID-19 pandemic.
When the ATP Tour resumed tournament play in August, Struff competed at the Western & Southern Open. This event usually takes place in Cincinnati but this year, it was held at the USTA Billie Jean King National Tennis Center in New York City in order to reduce unnecessary player travel by centralizing the tournament and the subsequent US Open in the same venue. He upset 12th seed and world No. 17, Denis Shapovalov, in the second round. He then upset seventh seed and world No. 10, David Goffin, in the third round to earn his best ATP Masters 1000 showing by reaching the quarterfinals. He ended up losing his quarterfinal match to world No. 1, 2018 champion, and eventual champion, Novak Djokovic. As a result, he entered the top 30 for the first time in his career and reached a career-high in singles of World No. 29 on 31 August 2020. Seeded 28th at the US Open, he made it to the third round where he was defeated by three-time champion Djokovic.
At the Italian Open, Struff lost in the first round to qualifier Federico Coria. In Hamburg, he was defeated in the first round by eighth seed and world No. 16, Karen Khachanov. Seeded 30th at the French Open, he was eliminated from the tournament in the second round by qualifier and compatriot, Daniel Altmaier.
Seeded seventh at the Bett1Hulks Indoors, Struff lost in the first round to qualifier and compatriot, Oscar Otte. Seeded seventh at the Bett1Hulks Championship, he was defeated in the second round by Yoshihito Nishioka. In Vienna, he was beaten in the first round by third seed and world No. 5, Stefanos Tsitsipas. At the Paris Masters, he lost in the second round to ninth seed and world No. 15, Pablo Carreño Busta. Struff played his final tournament of the season at the Sofia Open. Seeded fourth, he lost in the second round to eventual finalist Vasek Pospisil.
Struff ended the year ranked No. 36.
2021: ATP Cup semifinalist, first ATP Tour final Struff started his 2021 season at the Antalya Open. Seeded fifth, he reached the quarterfinals where he lost to Jérémy Chardy, despite having two match points in the third-set tie breaker. In February, he represented Germany with Alexander Zverev, Kevin Krawietz and Andreas Mies at the ATP Cup. Germany was in Group A alongside Canada and Serbia. He beat Milos Raonic of Canada, and Dušan Lajović of Serbia to help Germany qualify for the semifinals. In the semifinal tie against Russia, he lost to Andrey Rublev in three sets. In the end, Russia beat Germany 2-1 to advance to the ATP Cup final. At the Australian Open, he lost in the first round to Australian wildcard Christopher O'Connell.
Seeded eighth at the Open Sud de France, Struff was defeated in the first round by qualifier and compatriot, Peter Gojowczyk. In Rotterdam, he was beaten in the first round by sixth seed, world No. 14, and 2017 finalist, David Goffin. At the Dubai Championships, he lost in the second round to third seed and world No. 12, Denis Shapovalov. Seeded 31st at the Miami Open, he made it to the third round where he was eliminated by seventh seed and world No. 12, Roberto Bautista Agut.