Constantin Frantzen

Constantin Frantzen (born 16 March 1998) is a tennis player from Germany.

Doubles

 * 🇦🇹 Mauthausen (8 May 2023) – Romain Arneodo / 🇦🇹 Sam Weissborn def. 🇩🇪 Constantin Frantzen / 🇩🇪 Hendrik Jebens, 6–4, 6–2.
 * 🇩🇪 Heilbronn (5 Jun 2023) – 🇩🇪 Constantin Frantzen / 🇩🇪 Hendrik Jebens def. 🇷🇴 Victor Vlad Cornea / 🇦🇹 Philipp Oswald, 7–6(9–7), 6–4.
 * 🇫🇷 Lyon (12 Jun 2023) – 🇫🇷 Manuel Guinard / 🇫🇷 Grégoire Jacq def. 🇩🇪 Constantin Frantzen / 🇩🇪 Hendrik Jebens, 6–4, 2–6, [10–7].