Isabelle Haverlag

Isabelle Haverlag (born 4 March 2001) is a Dutch tennis player who specializes in doubles. She has a career-high doubles ranking of No. 65 by the WTA, achieved on 8 June 2026. She has won three WTA 125 doubles titles as well as 14 doubles titles on the ITF Women's World Tennis Tour.

Career She won her first big title at the 2022 Open de Seine-et-Marne, in the doubles draw, partnering Justina Mikulskytė.

In June 2022, she made her WTA Tour debut in doubles with compatriot Suzan Lamens at her home tournament, the Rosmalen Open, where as a wildcard pair they reached the quarterfinals defeating third seeds Kaitlyn Christian and Giuliana Olmos. In July 2024 at the Budapest Grand Prix, she reached the semifinals with Christina Rosca.

In February 2025 at the ATX Open, Haverlag and her partner Alicja Rosolska reached the semifinals defeating second seeded pair of former No. 1 doubles player Storm Hunter and former top 10 player Caroline Dolehide en route. Playing alongside Simona Waltert, she won her first WTA 125 doubles title at the 2025 Ilkley Open by defeating Vitalia Diatchenko and Eden Silva in the final.

Partnering Maia Lumsden, Haverlag reached her first WTA Tour final at the 2026 Mérida Open, losing to second seeds Cristina Bucșa and Jiang Xinyu. Once again teaming up with Lumsden, she won the second WTA 125 title at the 2026 Open de Saint-Malo, defeating Chan Hao-ching and Ivana Corley in the final.

Performance timeline

WTA Tour finals

Doubles: 1 (runner-up) LegendWTA 500 (1–0)WTA 250 (0–0)Finals by surfaceHard (1–0)

ResultW–LDateTournamentTierSurfacePartnerOpponentsScoreLoss 0–1 Mar 2026Mérida Open, MexicoWTA 500 Hard Maia Lumsden Cristina Bucșa Jiang Xinyu 4–6, 1–6

WTA 125 finals Doubles: 7 (4 titles, 3 runner-ups)

ITF Circuit finals Doubles: 37 (14 titles, 23 runner-ups) LegendW100 tournamentsW60/75 tournamentsW40/50 tournamentsW25/35 tournamentsW15 tournaments