Valentini Grammatikopoulou (; born 9 February 1997) is a Greek tennis player. On 22 August 2022, she reached her best singles ranking of world No. 143. On 15 July 2024, she peaked at No. 97 in the WTA doubles rankings. She has won a singles and a doubles title on the WTA Challenger Tour, and in addition, 15 singles and 35 doubles titles on the ITF Women's Circuit.

Playing for Greece, Grammatikopoulou has a win–loss record of 26–17 in Billie Jean King Cup competition (as of July 2025).

Career Playing with Ulrikke Eikeri, Grammatikopoulou reached her first WTA Tour doubles final at the 2021 Lausanne Open, losing to Susan Bandecchi and Simona Waltert in a deciding champions tiebreak.

She made her major debut at the 2021 US Open as a qualifier, after attempting to qualify 12 times for a major. It marked the first time ever that three Greek players were in the US Open main draw. On her major debut, she reached the second round after defeating Anna Blinkova, 6-3, 6-2. It was her third career win at the WTA Tour-level. Grammatikopoulou lost her next match to 15th seed Elise Mertens.

Grammatikopoulou qualified for her second Grand Slam tournament at the 2022 French Open, losing in the first round to wildcard entrant Daria Saville.

In August 2022, Grammatikopoulou won her biggest singles title to date at the WTA 125 Vancouver Open, defeating Lucia Bronzetti in the final.

Partnering Despina Papamichail, she won her first WTA 125 doubles title at the 2023 Barranquilla Open, overcoming Yuliana Lizarazo and María Paulina Pérez in the final.

Performance timelines

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

Singles Tournament20172018201920202021202220232024Grand Slam tournaments Australian OpenQ2Q2Q2AAQ1Q1Q20 / 00–0 French OpenQ2Q2Q3AA1RQ2Q10 / 10–1 WimbledonQ1Q1Q1NHAQ1Q11R0 / 10–1 US OpenQ1Q1Q1A2RAQ1A0 / 11–1Win–loss0–00–00–00–01–10–10–00–10 / 31–3WTA 1000Canadian OpenAAANHAQ1AA0 / 00–0Career statisticsTournaments2600310Career total: 12Overall win–loss0–21–60–10–11–30–10–10 / 122–15Year-end ranking212165265266185200217483$693,438

WTA Tour finals

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

ResultDateTournamentTierSurfacePartnerOpponentsScoreLossLadies Open Lausanne, SwitzerlandWTA 250Clay Ulrikke Eikeri Susan Bandecchi Simona Waltert3–6, 7–6(7–3), [5–10]

WTA 125 finals

Singles: 1 (title) ResultW–LDateTournamentSurfaceOpponentScoreWin1–0 Vancouver Open, CanadaHard Lucia Bronzetti6–2, 6–4

Doubles: 4 (1 title, 3 runner-ups) ResultW–LDateTournamentSurfacePartnerOpponentsScoreLoss0–1 Korea Open, South KoreaHard (i) Réka Luca Jani Choi Ji-hee Han Na-lae4–6, 4–6Win1–1 Barranquilla Open, ColombiaHard Despina Papamichail Yuliana Lizarazo María Paulina Pérez7–6(7–2), 7–5Loss1–2 Bari Open, ItalyClay Elixane Lechemia Katarzyna Kawa Anna Sisková1–6, 2–6Loss1–3 Open Romania Ladies, RomaniaClay Anna Sisková Angelica Moratelli Camilla Rosatello5–7, 4–6

ITF Circuit finals

Singles: 32 (16 titles, 16 runner-ups) LegendW40 tournaments (1–0) W25/35 tournaments (6–8)W10/15 tournaments (9–8)

ResultW–LDateTournamentTierSurfaceOpponentScoreWin 1–0 Apr 2013ITF Heraklion, GreeceW10 Carpet Amy Bowtell 6–3, 6–4Win 2–0 May 2013ITF Heraklion, GreeceW10 Carpet Lee Pei-chi 7–6(4), 3–6, 6–2Win 3–0 Aug 2013ITF Pirot, SerbiaW10 Clay Eva Wacanno 6–1, 6–4Win 4–0 Sep 2014ITF Vrnjačka Banja, SerbiaW10 Clay Dea Herdželaš 1–6, 6–3, 7–6(5)Loss 4–1 Nov 2014ITF Heraklion, GreeceW10 Hard Dalma Gálfi 2–6, 6–4, 6–7(4)Loss 4–2 Apr 2015ITF Heraklion, GreeceW10 Hard Maria Sakkari 2–6, 2–6Loss 4–3 Apr 2015ITF Heraklion, GreeceW10 Hard Viktória Kužmová 3–6, 4–6Win 5–3 Aug 2015ITF Oldenzaal, NetherlandsW10 Clay Katharina Lehnert 7–6(2), 6–3Loss 5–4 Aug 2015ITF Rotterdam, NetherlandsW10 Clay Chayenne Ewijk 6–7(3), 3–6Win 6–4 Oct 2015ITF Port El Kantaoui, TunisiaW10 Hard Caroline Roméo 2–6, 6–2, 6–3Loss 6–5 Oct 2015ITF Port El Kantaoui, TunisiaW10 Hard Valeriya Strakhova 2–6, 0–6Win 7–5 Oct 2015ITF Heraklion, GreeceW10 Hard Pemra Özgen 3–6, 6–3, 6–3Win 8–5 Nov 2015ITF Heraklion, GreeceW10 Hard Julia Stamatova 7–5, 6–1Loss 8–6 Jan 2016ITF Stuttgart, GermanyW10 Hard (i) Anna Blinkova 6–7(4), 6–2, 2–6Win 9–6 Jun 2016ITF Minsk, BelarusW25 Clay Anna Kalinskaya 6–3, 4–1 ret.Loss 9–7 Jul 2016ITF Middelburg, NetherlandsW25 Clay Quirine Lemoine 2–6, 5–7Loss 9–8 Aug 2016ITF Westende, BelgiumW25 Hard Anna Blinkova 5–7, 2–6Loss 9–9 Aug 2016ITF Kharkiv, UkraineW25 Clay Anna Kalinskaya 4–6, 6–1, 1–6Win 10–9 Dec 2016ITF Hammamet, TunisiaW10 Hard Jelena Simić 6–1, 6–3Loss 10–10 Jul 2017ITF Middelburg, NetherlandsW25 Clay Arantxa Rus 6–3, 2–6, 3–6Win 11–10 Nov 2017ITF Dakar, SenegalW25 Hard Chanel Simmonds 6–0, 7–6(1)Loss 11–11 Aug 2018ITF Chiswick, United KingdomW25 Hard Vitalia Diatchenko 1–6, 5–7Loss 11–12 Jun 2021Tatarstan Open, RussiaW25 Hard Anna Kubareva 1–6, 3–6Win 12–12 Jul 2021Telavi Open, GeorgiaW25 Clay Tessah Andrianjafitrimo 7–5, 6–4Win 13–12 May 2023ITF Santa Margherita di Pula, Italy W25 Clay Kathinka von Deichmann 6–4, 6–1Win 14–12 Jun 2023ITF Otočec, Slovenia W40 Clay Rebecca Šramková 6–4, 6–4Win 15–12 Oct 2023ITF Sharm El Sheikh, Egypt W25 Hard Linda Klimovičová 7–6(1), 7–5Loss 15–13 Nov 2024ITF Solarino, ItalyW35 Carpet Joanna Garland 7–5, 2–6, 3–6Loss 15–14 Jun 2025ITF Focșani, RomaniaW15 Clay Ruth Roura Llaverias 6–7(4), 6–7(5)Loss 15–15 Jul 2025ITF Turin, ItalyW35 Clay Ane Mintegi del Olmo 3–6, 1–6Loss 15–16 May 2026ITF Tsaghkadzor, ArmeniaW15 Clay Kristina Kroitor 1–6, 2–6Win16–16Aug 2026ITF Verbier, SwitzerlandW35Clay Jenny Lim 6–4, 6–1

Doubles: 63 (35 titles, 28 runner-ups) LegendW100 tournaments (1–1) W80 tournaments (0–1)W60/75 tournaments (5–3)W40 tournaments (0–1)W25/35 tournaments (21–15)W10/15 tournaments (8–7)