Constantin Frantzen (born 16 March 1998) is a German professional tennis player who specializes in doubles. He has a career-high ATP doubles ranking of world No. 29 achieved on 24 August 2026.
Frantzen has won one ATP Tour doubles title at the 2025 Chengdu Open, with Robin Haase.
He played college tennis at Baylor University.
Career
2023–2024: ATP and major debuts in doubles Frantzen made his ATP Tour doubles main draw debut at the Swiss Open Gstaad alongside Hendrik Jebens.
He reached his first ATP Tour final at the Moselle Open with partner Jebens, but lost to Hugo Nys and Jan Zieliński. Frantzen reached his second ATP Tour final at the 2024 Generali Open Kitzbühel also alongside Jebens but lost to Alexander Erler and Andreas Mies. The pair also made it to the 2024 Hangzhou Open final, losing to Jeevan Nedunchezhiyan and Vijay Sundar Prashanth in the final.
2025: Maiden ATP title In September, Frantzen won his first doubles title on the ATP Tour at the Chengdu Open, playing alongside Robin Haase.
Doubles performance timeline
Current through the 2026 China Open.
Tournament2023202420252026SRW–LGrand Slam tournamentsAustralian OpenA1R1R1R0 / 30–3French OpenA1R2R1R0 / 31–3WimbledonAQF3R1R0 / 35–3US OpenA1RQF1R0 / 33–3Win–loss0–03–46–40–40 / 129–12ATP 1000 tournamentsIndian Wells OpenAA1RQF0 / 22–2Miami OpenAA1R1R0 / 20–2Madrid OpenAA2RA0 / 11–1Cincinnati OpenAAAF0 / 14–1Win–loss0–00–01–36–30 / 67–6Career statisticsTournaments520252474Titles00101Finals12137Overall win–loss3–519–2023–2324–2469–72Year-end ranking655248
Significant finals
ATP 1000 tournaments
Doubles: 1 (runner-up) ResultYearTournamentSurfacePartnerOpponentsScoreLoss2026Cincinnati OpenHard Robin Haase Orlando Luz Rafael Matos4–6, 6–3, [7–10]
ATP Tour finals
Doubles: 7 (1 title, 6 runner-ups) LegendGrand Slam (–)ATP 1000 (0–1)ATP 500 (0–1)ATP 250 (1–4)Finals by surfaceHard (1–4)Clay (0–2)Grass (–)Finals by settingOutdoor (1–3)Indoor (0–2)
ResultW–LDateTournamentTierSurfacePartnerOpponentsScoreLoss0–1Moselle Open, FranceATP 250Hard (i) Hendrik Jebens Hugo Nys Jan Zieliński4–6, 4–6Loss0–2Austrian Open, AustriaATP 250Clay Hendrik Jebens Alexander Erler Andreas Mies3–6, 6–3, [6–10]Loss0–3Hangzhou Open, ChinaATP 250Hard Hendrik Jebens Jeevan Nedunchezhiyan Vijay Sundar Prashanth6–4, 6–7(5–7), [7–10]Win1–3Chengdu Open, ChinaATP 250Hard Robin Haase Vasil Kirkov Bart Stevens4–6, 6–3, [10–7]Loss1–4Open Occitanie, FranceATP 250Hard (i) Robin Haase Théo Arribagé Albano Olivetti6–7(6–8), 1–6Loss1–5Rio Open, BrazilATP 500Clay Robin Haase João Fonseca Marcelo Melo6–4, 3–6, [8–10]Loss1–6Cincinnati Open, United StatesATP 1000Hard Robin Haase Orlando Luz Rafael Matos4–6, 6–3, [7–10]
ATP Challenger finals
Doubles: 18 (9 titles, 9 runner-ups) Finals by surfaceHard (2–5)Clay (7–3)Carpet (0–1)
ResultW–LDateTournamentSurfacePartnerOpponentsScoreLoss0–1Columbus, United StatesHard Charles Broom Julian Cash Henry Patten2–6, 5–7Loss0–2Las Vegas, United StatesHard Reese Stalder Julian Cash Henry Patten4–6, 6–7(1–7)Loss0–3Pau, FranceHard (i) Julian Cash Dan Added Albano Olivetti6–3, 1–6, [8–10]Loss0–4Lugano, SwitzerlandHard (i) Hendrik Jebens Zizou Bergs David Pel2–6, 6–7(6–8)Win1–4Biel/Bienne, SwitzerlandHard (i) Hendrik Jebens Victor Vlad Cornea Franko Škugor6–2, 6–4Loss1–5Mauthausen, AustriaClay Hendrik Jebens Romain Arneodo Sam Weissborn4–6, 2–6Win2–5Heilbronn, GermanyClay Hendrik Jebens Victor Vlad Cornea Philipp Oswald7–6(9–7), 6–4Loss2–6Lyon, FranceClay Hendrik Jebens Manuel Guinard Grégoire Jacq4–6, 6–2, [7–10]Win3–6Augsburg, GermanyClay Hendrik Jebens Constantin Kouzmine Volodymyr Uzhylovskyi6–2, 6–2Win4–6Como, ItalyClay Hendrik Jebens Filip Bergevi Mick Veldheer6–3, 6–4Win5–6Bad Waltersdorf, AustriaClay Hendrik Jebens Marco Bortolotti Francesco Passaro6–1, 6–2Win6–6Orléans, FranceHard (i) Hendrik Jebens Henry Patten John-Patrick Smith7–6(7–5), 7–6(14–12)Loss6–7Ismaning, GermanyCarpet (i) Hendrik Jebens Sriram Balaji Andre Begemann6–7(4–7), 4–6Loss6–8Lugano, SwitzerlandHard (i) Hendrik Jebens Sander Arends Sem Verbeek7–6(11–9), 6–7(1–7), [8–10]Win7–8 Mauthausen, AustriaClay Hendrik Jebens Ryan Seggerman Patrik Trhac6–4, 6–4Win8–8Naples, ItalyClay Alexander Erler Geoffrey Blancaneaux Albano Olivetti6–4, 6–4Loss8–9Sassuolo, ItalyClay Alexander Erler Matthew Romios Ryan Seggerman6–7(4–7), 6–3, [7–10]Win9–9Valencia, SpainClay Robin Haase Sander Arends David Pel6–4, 6–7(5–7), [11–9]
ITF Tour finals
Doubles: 11 (5 titles, 6 runner-ups) Finals by surfaceHard (1–4)Clay (3–2)Carpet (1–0)
ResultW–LDateTournamentSurfacePartnerOpponentsScoreWin1–0Ismaning, GermanyCarpet (i) Alexander Erler Kevin Krawietz Tim Sandkaulen2–6, 7–5(7–5), [10–8]Loss1–1M15 Lubbock, United StatesHard Sven Lah Sekou Bangoura Gijs Brouwer4–6, 6–4, [5–10]Loss1–2M25 Harlingen, United StatesHard Gabi Adrian Boitan Francis Alcantara Mark Whitehouse6–7(3–7), 7–5, [7–10]Loss1–3M25 Glasgow, United KingdomHard (i) Charles Broom Gijs Brouwer Aidan McHugh6–4, 6–7(1–7), [4–10]Loss1–4M15 Monastir, TunisiaHard Tim Sandkaulen Szymon Kielan Michał Mikuła6–7(4–7), 7–6(7–2), [2–10]Win2–4M15 Monastir, TunisiaHard Charles Broom Li Zhe Bu Yunchaokete7–5, 2–6, [10–8]Win3–4M15 Meerbusch, GermanyClay Tim Sandkaulen Miguel Fernando Pereira Gabriel Roveri Sidney7–6(7–5), 6–4Win4–4M25 Most, Czech RepublicClay Tim Sandkaulen Marek Gengel David Poljak6–3, 4–6, [10–7]Loss4–5M25 Arlon, BelgiumClay Tim Sandkaulen Anirudh Chandrasekar Vijay Sundar Prashanth6–7(5–7), 4–6Win5–5M25 Kassel, GermanyClay Tim Sandkaulen Tom Gentzsch Leopold Zima6–4, 6–2Loss5–6M25 Wetzlar, GermanyClay Tim Sandkaulen Benjamin Hassan Tristan Lamasine4–6, 3–6
References
External links