Katarzyna Piter (; born 16 February 1991) is a Polish professional tennis player who specializes in doubles.

On 12 May 2014, she reached her career-high ranking of No. 95 in singles and on 9 June 2025, she achieved her best doubles ranking of No. 49. Piter has won six doubles titles on the WTA Tour and two on WTA 125 tournaments, as well as eight singles and 26 doubles titles on the ITF Women's Circuit.

Career In July 2013, at the Palermo Ladies Open, Piter won her first title on the WTA Tour. She and partner Kristina Mladenovic upset Karolína and Kristýna Plíšková in the final, in a super-tiebreak.

Partnered with Fanny Stollár, she also won the doubles title at the 2023 Budapest Grand Prix, defeating Jessie Aney and Anna Sisková inna champions tiebreak in the final. The pair defended their title in Budapest the following year, beating Anna Danilina and Irina Khromacheva in the final which again went to a deciding champions tiebreak. Piter and Stollár were runners-up in the doubles at the 2024 Guangzhou Open, losing to top seeds Kateřina Siniaková and Zhang Shuai in the final. They also lost in the final at the 2024 Jiangxi Open, this time to Guo Hanyu and Moyuka Uchijima.

Teaming with Mayar Sherif, she won the 2025 Mérida Open, defeating Anna Danilina and Irina Khromacheva in the final. Piter combined with Janice Tjen to claim the 2025 Guangzhou Open, overcoming Eudice Chong and Liang En-shuo in the final which went to a deciding champions tiebreak.

Fed Cup Piter played 2009 for Poland in the Europe/Africa Zone I of the Fed Cup and helped them qualify for the World Group II Play-offs against Japan. In the round-robin stage, she lost her match against Monica Niculescu of Romania, won against Johanna Larsson of Sweden, beat Dijana Stojić of Bosnia and Herzegovina and paired up with Klaudia Jans to beat the Bosnian pairing. In the first play-off against Great Britain, she lost the first singles match to Elena Baltacha, 4–6, 1–6. Poland, however, won that tie.

Performance timelines

Only main-draw results in WTA Tour, Grand Slam tournaments, Billie Jean King Cup, United Cup, Hopman Cup and Olympic Games are included in win–loss records.

Singles Tournament200720082009201020112012201320142015201620172018...2021Grand Slam tournaments Australian OpenAAAAAAA1RQ3AAAA0–1 French OpenAAAAAAA1RAAAAA0–1 WimbledonAAAAAAA1RAAAAA0–1 US OpenAAAAAAQ21RQ2AQ1AA0–1Win–loss0–00–00–00–00–00–00–00–40–00–00–00–00–00–4National representationBillie Jean King CupAAPO2AAAPO2WG2AAZ1AA4–5WTA 1000Indian Wells OpenAAAAAAAQ1AAAAA0–0Miami OpenAAAAAAA1RAAAAA0–1Madrid OpenAAAAAAAQ2AAAAA0–0Italian OpenAAAAAAAQ1AAAAA0–0Win–loss0–00–00–00–00–00–00–00–10–00–00–00–00–00–1Career statisticsTournaments10110021201011Career total: 20Overall win–loss0–10–02–31–10–00–03–24–140–00–12–10–10–112–25Year-end ranking675466330242324376122162218239345297493

Doubles Current through the 2025 Madrid Open Tournament20092010201120122013201420152016201720182019202020212022202320242025SRW–LWin%Grand Slam tournaments Australian OpenAAAAA2R1RAAAAAA1RA1R1R0 / 51–5 French OpenAAAAA2RAAAAAAA1R2R1R1R0 / 52–5 WimbledonAAAAA1RAAAAANHA1R1R1R1R0 / 50–5 US OpenAAAAA2RAAAAAAA1R1R1R1R0 / 51–5Win–loss0–00–00–00–00–03–40–10–00–00–00–00–00–00–41–30–40–40 / 204–20WTA 1000Madrid OpenAAAAAAAAAAAA1R1RA2R1R0 / 41–4Italian OpenAAAAA1RAAAAAAAAAA1R0 / 20–2Win–loss0–00–00–00–00–00–10–00–00–00–00–00–00–10–10–00 / 30–3Career statisticsTournaments0030101866221017155Career total: 85Titles000010000000001Career total: 2Finals001011010000212Career total: 9Overall win–loss1–00–04–30–013–912–185–66–64–31–20–10–011–178–158–42 / 8573–84Year-end ranking322385129183817814611624721324813493114676359

WTA Tour finals

Doubles: 15 (6 titles, 10 runner-ups) LegendGrand SlamWTA 1000WTA 500 (1–0)WTA 250 (5–10)Finals by surfaceHard (3–4)Clay (3–6)

ResultW–LDateTournamentTierSurfacePartnerOpponentsScoreLoss0–1Jun 2011Danish Open, DenmarkInternationalHard Kristina Mladenovic Johanna Larsson Jasmin Wöhr3–6, 3–6Win1–1Jul 2013Palermo Ladies Open, ItalyInternationalClay Kristina Mladenovic Karolína Plíšková Kristýna Plíšková6–1, 5–7, [10–8]Loss1–2Apr 2014Marrakesh Grand Prix, MoroccoInternationalClay Maryna Zanevska Garbiñe Muguruza Romina Oprandi6–4, 2–6, [9–11]Loss1–3Jul 2016Bucharest Open, RomaniaInternationalClay Alexandra Cadanțu Jessica Moore Varatchaya Wongteanchai3–6, 6–7(5–7)Loss1–4Jul 2021Poland Open, PolandWTA 250Clay Kateryna Bondarenko Anna Danilina Lidziya Marozava3–6, 2–6Loss1–5Aug 2021Cluj-Napoca Open, RomaniaWTA 250Clay Mayar Sherif Natela Dzalamidze Kaja Juvan3–6, 4–6Loss1–6Jul 2022Budapest Grand Prix, HungaryWTA 250Clay Kimberley Zimmermann Ekaterine Gorgodze Oksana Kalashnikova6–1, 4–6, [6–10]Loss1–7Copa Colsanitas, ColombiaWTA 250Clay Oksana Kalashnikova Irina Khromacheva Iryna Shymanovich1–6, 6–3, [6–10]Win2–7Jul 2023Budapest Grand Prix, HungaryWTA 250Clay Fanny Stollár Jessie Aney Anna Sisková6–2, 4–6, [10–4]Loss2–8Jul 2023Poland Open, PolandWTA 250Hard Weronika Falkowska Heather Watson Yanina Wickmayer4–6, 4–6Win3–8Jul 2024Budapest Grand Prix, Hungary (2)WTA 250Clay Fanny Stollár Anna Danilina Irina Khromacheva6–3, 3–6, [10–3]Loss3–9Oct 2024Guangzhou Open, ChinaWTA 250Hard Fanny Stollár Kateřina Siniaková Zhang Shuai4–6, 1–6Loss3–10Jiangxi Open, ChinaWTA 250Hard Fanny Stollár Guo Hanyu Moyuka Uchijima6–7(5–7), 5–7Win4–10Mérida Open, MexicoWTA 500Hard Mayar Sherif Anna Danilina Irina Khromacheva7–6(7–2), 7–5Win5–10Guangzhou Open, ChinaWTA 250Hard Janice Tjen Eudice Chong Liang En-shuo3–6, 6–3, [10–5]Win6–10Hobart International, AustraliaWTA 250Hard Janice Tjen Magali Kempen Anna Sisková6–2, 6–2

WTA 125 finals Doubles: 7 (2 titles, 5 runner-ups) ResultW–LDateTournamentSurfacePartnerOpponentsScoreLoss0–1Karlsruhe Open, GermanyClay Mayar Sherif Irina Bara Ekaterine Gorgodze3–6, 6–2, [7–10]Loss0–2Apr 2023San Luis Open, MexicoClay Oksana Kalashnikova Aliona Bolsova Andrea Gámiz6–7(5–7), 4–6Loss0–3Veneto Open, ItalyGrass Weronika Falkowska Han Na-lae Jang Su-jeong3–6, 6–3, [6–10]Loss0–4San Luis Open, MexicoClay Laura Pigossi Anna Bondár Tamara Zidanšekw/oLoss0–5Catalonia Open, SpainClay Mayar Sherif Nicole Melichar-Martinez Ellen Perez5–7, 2–6Win1–5Internacional de Valencia, SpainClay Fanny Stollár Angelica Moratelli Renata Zarazúa6–1, 4–6, [10–8]Win2–5Guadalajara Open, MexicoHard Fanny Stollár Angelica Moratelli Sabrina Santamaria6–4, 7–5

ITF Circuit finals Singles: 20 (8 titles, 12 runner-ups) Legend$100,000 tournaments (0–1)$25,000 tournaments (3–7)$10,000 tournaments (5–4)Finals by surfaceHard (2–3)Clay (6–8)Carpet (0–1) ResultW–LDateTournamentTierSurfaceOpponentScoreLoss 0–1 May 2007ITF Michalovce, Slovakia10,000 Clay Kristína Kučová 6–2, 3–6, 4–6Win 1–1 Aug 2007ITF Bielefeld, Germany10,000 Clay Dominice Ripoll 3–6, 6–3, 6–4Win 2–1 Mar 2008ITF Ain Sukhna, Egypt10,000 Clay Irina-Camelia Begu 7–6(9–7), 6–4Win 3–1 Mar 2008ITF Cairo, Egypt10,000 Clay Bibiane Schoofs 6–1, 6–3Win 4–1 Nov 2008ITF Jersey, United Kingdom10,000 Hard (i) Stefania Boffa 6–2, 6–2Loss 4–2 Jul 2009ITF Brussels, Belgium10,000 Clay Maryna Zanevska 6–0, 5–7, 5–7Win 5–2 Mar 2010GB Pro-Series Bath, UK10,000 Hard (i) Lenka Juríková 6–2, 7–6(8–6)Win 6–2 Aug 2010ITF Koksijde, Belgium25,000 Clay Kiki Bertens 6–4, 6–4Loss 6–3 Sep 2011ITF Alphen aan den Rijn, Netherlands25,000 Clay Stephanie Vogt 2–6, 4–6Loss 6–4 Feb 2012ITF Tallinn, Estonia10,000 Hard (i) Anett Kontaveit 5–7, 4–6Loss 6–5 Mar 2012GB Pro-Series Bath, UK10,000 Hard (i) Tereza Smitková 6–4, 2–6, 1–6Loss 6–6 Jun 2013Grado Tennis Cup, Italy25,000 Clay Yvonne Meusburger 2–6, 7–6(7–2), 3–6Loss 6–7 Jul 2013Bella Cup Toruñ, Poland25,000 Clay Paula Kania 4–6, 4–6Loss 6–8 Jul 2013ITS Cup Olomouc, Czech Republic100,000 Clay Polona Hercog 0–6, 3–6Loss 6–9 Aug 2013ITF Izmir, Turkey25,000 Hard Ana Vrljić 1–6, 3–6Win 7–9 May 2015Grado Tennis Cup, Italy25,000 Clay Kristina Schmiedlová 6–3, 6–0Loss 7–10 Aug 2016ITF Bagnatica, Italy25,000 Clay Martina Trevisan 1–6, 7–5, 5–7Win 8–10 Jan 2017ITF Orlando, United States25,000 Clay Sofia Kenin 6–7(4–7), 6–2, 6–4Loss 8–11 Nov 2017ITF Zawada, Poland25,000 Carpet (i) Deborah Chiesa 2–6, 6–4, 4–6Loss 8–12 Jul 2018ITF Horb, Germany25,000 Clay Katharina Gerlach 6–4, 3–6, 6–7(4–7)

Doubles: 50 (26 titles, 24 runner-ups) Legend$100,000 tournaments (2–1)$75/80,000 tournaments (1–2)$50/60,000 tournaments (2–0)$25,000 tournaments (18–20)$10,000 tournaments (3–1)Finals by surfaceHard (8–9)Clay (16–13)Carpet (2–2)