Marius Copil (born 17 October 1990) is a former Romanian professional tennis player. He reached a career-high ATP singles ranking of world No. 56 on 28 January 2019. Copil was known for his extremely fast, powerful, and consistent serve. He was a member of the Romanian Davis Cup team.
The 2011 season started well for Copil, when he reached his second Challenger final at the Tretorn Serie+ event in Kazan, Russia. In the final, he won against fourth seed German Andreas Beck, in straight sets.
In 2012, Copil beat world No. 13 Marin Čilić in the first round at the China Open in Beijing.
At the 2015 Romanian Open in April, partnering fellow Romanian Adrian Ungur, after saving five match points, they defeated Nicholas Monroe/Artem Sitak 17–15 in the match tiebreak to become the first Romanian team to win the Bucharest title since 1998 (Pavel/Trifu). At the 2015 's-Hertogenbosch Open, Copil defeated Jarkko Nieminen and Guillermo García López as a wildcard to reach the quarterfinals.
Copil made his top 100 singles debut after the 2017 Mutua Madrid Open, where he was a wildcard entry, at World No. 90 on 15 May 2017.
Ranked No. 93, Copil reached the final of the Swiss Indoors in Basel as a qualifier, losing to Roger Federer after defeating world No. 6 Marin Čilić and No. 5 Alexander Zverev on the way, his first ever wins over top-10 players. He became the lowest-ranked Basel finalist since No. 100 Patrick McEnroe in 1994 and the first qualifier in the final since Baghdatis in 2005.
His best showing in doubles at a Grand Slam in his career was reaching the third round of the 2019 French Open partnering Rohan Bopanna. He also reached the second round of the 2019 US Open for the first time in his career in singles and doubles.
Copil underwent surgery on 30 May 2024 and came back to the ITF tour five months later in October.
Copil announced his retirement from professional tennis in November 2025.
| Grand Slam tournaments | ||||||||||||||||||||
| Australian Open | A | A | A | A | A | A | A | A | Q1 | Q2 | 2R | Q2 | Q1 | 1R | 2R | Q2 | Q1 | A | 2–3 | |
| French Open | A | A | A | A | A | A | Q2 | A | Q1 | Q2 | Q3 | Q3 | 1R | 1R | 1R | Q1 | Q1 | Q2 | 0–3 | |
| Wimbledon | A | A | A | A | A | A | A | A | A | Q2 | Q2 | 1R | 1R | 1R | 1R | NH | Q2 | Q1 | 0–4 | |
| US Open | A | A | A | A | A | A | Q2 | Q3 | Q1 | Q1 | Q2 | Q1 | 1R | 1R | 2R | A | Q2 | A | 1–3 | |
| {class="wikitable" style=font-size:90% !Legend |
| Grand Slam (0–0) |
| ATP 1000 (0–0) |
| ATP 500 (0–1) |
| ATP 250 (0–1) |
| Hard (0–2) |
| Clay (0–0) |
| Grass (0–0) |
| Outdoor (0–0) |
| Indoor (0–2) |
| Loss | 0–1 | Sofia Open, Bulgaria | ATP 250 | Hard (i) | Mirza Bašić | 6–7(6–8), 7–6(7–4), 4–6 | |
| Loss | 0–2 | Swiss Indoors, Switzerland | ATP 500 | Hard (i) | Roger Federer | 6–7(5–7), 4–6 |
| {class="wikitable" style=font-size:90% !Legend |
| Grand Slam (0–0) |
| ATP 1000 (0–0) |
| ATP 500 (0–0) |
| ATP 250 (1–0) |
| Hard (0–0) |
| Clay (1–0) |
| Grass (0–0) |
| Outdoor (1–0) |
| Indoor (0–0) |
| Win | 1–0 | Romanian Open, Romania | ATP 250 | Clay | Adrian Ungur | Nicholas Monroe Artem Sitak | 3–6, 7–5, 17–15 |
| 2009 World Group play-offs | PO | 18–20 September 2009 | Sweden | Hard (i) | Andreas Vinciguerra | Win | 4–6 ret. |
| 2010 Europe/Africa Zone Group I | QF | 7–8 May 2010 | Ukraine | Clay | Ivan Sergeyev | Unfinished | 4–6, 2–1 |
| 2011 World Group play-offs | PO | 16–18 September 2011 | Czech Republic | Clay | Lukáš Rosol | Lose | 4–6, 6–7(2–7) |
| 2012 Europe/Africa Zone Group I | 1R PO | 14–16 September 2012 | Finland | Hard (i) | Harri Heliövaara | Win | 3–6, 6–4, 6–2, 6–4 |
| Jarkko Nieminen | Lose | 3–6, 5–7, 6–1, 6–7(4–7) | |||||
| 2013 Europe/Africa Zone Group I | 1R | 1–3 February 2013 | Denmark | Hard (i) | Frederik Nielsen | Win | 6–3, 7–6(9–7), 6–4 |
| Christoffer Kønigsfeldt | Win | 6–4, 6–3 | |||||
| 2R | 5–7 April 2013 | Netherlands | Hard | Thiemo de Bakker | Lose | 6–7(3–7), 6–7(2–7) | |
| 2014 Europe/Africa Zone Group I | 1R PO | 12–14 September 2014 | Sweden | Clay | Elias Ymer | Win | 6–2, 6–3, 6–2 |
| 2015 Europe/Africa Zone Group I | 1R | 6–8 March 2015 | Israel | Hard (i) | Dudi Sela | Win | 6–7(3–7), 7–6(7–3), 6–4, 6–2 |
| Bar Tzuf Botzer | Win | 7–6(7–3), 6–3 | |||||
| 2R | 17–19 July 2015 | Slovakia | Clay | Norbert Gombos | Win | 7–6(7–5), 6–7(6–8), 6–4, 7–6(12–10) | |
| Martin Kližan | Lose | 7–6(7–3), 6–3 | |||||
| 2016 Europe/Africa Zone Group I | 1R | 4–6 March 2016 | Slovenia | Hard (i) | Blaž Rola | Win | 7–5, 6–3, 7–6(7–5) |
| Tomislav Ternar | Win | 6–3, 6–3 | |||||
| 2R | 15–17 July 2016 | Spain | Hard | Feliciano López | Lose | 6–7(7-7), 7–5, 4–6, 6–3, 3–6 | |
| 2017 Europe/Africa Zone Group I | 1R | 3–5 February 2017 | Belarus | Hard (i) | Egor Gerasimov | Lose | 3–6, 4–6, 4–6 |
| Ilya Ivashka | Win | 7–5, 6–3, 6–1 | |||||
| 2018 Europe/Africa Zone Group II | 1R | 3–4 February 2018 | Luxembourg | Hard (i) | Christophe Tholl | Win | 6–3, 6–2 |
| Ugo Nastasi | Win | 6–1, 6–1 | |||||
| 2R | 7–8 April 2019 | Morocco | Hard (i) | Amine Ahouda | Win | 6–0, 6–1 | |
| 3R | 15–16 September 2019 | Poland | Clay (i) | Kamil Majchrzak | Win | 6–2, 6–4 | |
| Hubert Hurkacz | Lose | 3–6, 4–6 | |||||
| 2019 Europe/Africa Zone Group II | — | 5–6 April 2019 | Zimbabwe | Hard (i) | Benjamin Lock | Lose | 4–6, 5–7 |
| Takanyi Garanganga | Win | 6–4, 7–5 | |||||
| 2020–2021 World Group I | PO | 17–19 September 2021 | Portugal | Hard (i) | Gastão Elias | Win | 6–4, 6–3 |
| Gastão Elias | Win | 6–3, 2–6, 6–4 |
| 2009 World Group | 1R | 6–8 March 2009 | Horia Tecău | Russia | Hard (i) | Marat Safin Dmitry Tursunov | Win | 4–6, 6–7(2–7), 7–6(7–4), 7–6(7–5), 6–4 |
| 2011 World Group play-offs | PO | 16–18 September 2011 | Horia Tecău | Czech Republic | Clay | Tomáš Berdych Radek Štěpánek | Lose | 6–3, 3–6, 0–6, 2–6 |
| 2014 Europe/Africa Zone Group I | 1R | 31 January – 2 February 2014 | Horia Tecău | Ukraine | Hard | Sergei Bubka Denys Molchanov | Win | 5–7, 6–3, 6–4, 6–4 |
| {class="wikitable" style=font-size:97% !Legend |
| ATP Challenger (3–9) |
| ITF Futures/WTT (5–4) |
| Hard (5–8) |
| Clay (3–3) |
| Grass (0–1) |
| Carpet (0–1) |
| Win | 1–0 | Romania F16, Arad | Futures | Clay | Martín Alund | 6–4, 6–3 | |
| Win | 2–0 | Romania F16, Deva | Futures | Clay | Andrei Mlendea | 6–3, 7–6(7–5) | |
| Loss | 2–1 | Romania F14, Arad | Futures | Clay | Attila Balázs | 6–3, 5–7, 3–6 | |
| Loss | 2–2 | Greece F3, Paros | Futures | Carpet | Petar Jelenic | 6–2, 4–6, 6–7(2–7) | |
| Win | 3–2 | Guatemala F1, Guatemala City | Futures | Hard | Iván Endara | 7–6(7–5), 7–6(7–3) | |
| Loss | 0–1 | Cremona, Italy | Challenger | Hard | Denis Gremelmayr | 4–6, 5–7 | |
| Loss | 3–3 | Germany F2, Stuttgart | Futures | Hard | Jan Mertl | 6–2, 3–6, 4–6 | |
| Win | 1–1 | Kazan, Russia | Challenger | Hard | Andreas Beck | 6–4, 6–4 | |
| Loss | 3–4 | Romania F1, Bucharest | Futures | Clay | Petru-Alexandru Luncanu | 6–3, 4–6, 5–7 | |
| Loss | 1–2 | Kazan, Russia | Challenger | Hard | Jürgen Zopp | 6–7(4–7), 6–7(4–7) | |
| Win | 2–2 | Quimper, France | Challenger | Hard | Marc Gicquel | 7–6(11–9), 6–4 | |
| Loss | 2–3 | Arad, Romania | Challenger | Clay | Adrian Ungur | 4–6, 6–7(3–7) | |
| Loss | 2–4 | Guimarães, Portugal | Challenger | Hard | João Sousa | 3–6, 0–6 | |
| Loss | 2–5 | İzmir, Tunisia | Challenger | Hard | Lukaš Lacko | 3–6, 6–7(5–7) | |
| Loss | 2–6 | Surbiton Trophy, United Kingdom | Challenger | Grass | Lu Yen-hsun | 5–7, 6–7(11–13) | |
| Win | 3–6 | Budapest, Hungary | Challenger | Hard | Steve Darcis | 6–4, 6–2 | |
| Loss | 3–7 | Slovak Open, Slovakia | Challenger | Hard | Norbert Gombos | 6–7(8–10), 6–4, 3–6 | |
| Loss | 3–8 | OEC Kaohsiung, Taiwan | Challenger | Hard | Evgeny Donskoy | 6–7(0–7), 5–7 | |
| Loss | 3–9 | Slovak Open, Slovakia | Challenger | Hard | Lukáš Lacko | 4–6, 6–7(4–7) | |
| Win | 4–4 | M25 Portimão, Portugal | WTT | Hard | Alexey Vatutin | 7–5, 6–2 | |
| Win | 5–4 | M25 Bacău, Romania | WTT | Clay | Hernán Casanova | 6–3, 7–6(7–4) |
| {class="wikitable" style=font-size:97% !Legend |
| ATP Challenger (2–3) |
| ITF Futures (7–7) |
| Hard (3–2) |
| Clay (5–8) |
| Carpet (1–0) |
| Win | 1–0 | Romania F16, Deva | Futures | Clay | Ilie-Aurelian Giurgiu | Bojan Szumanski Hubert Holzler | 6–3, 6–2 | |
| Win | 2–0 | Germany F5, Nussloch | Futures | Carpet | Petru-Alexandru Luncanu | Jonathan Marray Rasmus Nørby | walkover | |
| Win | 3–0 | Romania F1, Craiova | Futures | Clay | Petru-Alexandru Luncanu | Andrei Ciumac Radu Albot | 7–5, 6–1 | |
| Loss | 3–1 | Romania F9, Iași | Futures | Clay | Victor Ioniță | Gleb Alekseenko Vadim Alekseenko | 3–6, 6–2, 7–10 | |
| Loss | 3–2 | Romania F10, Cluj-Napoca | Futures | Clay | Ilie-Aurelian Giurgiu | Gleb Alekseenko Vadim Alekseenko | 4–6, 4–6 | |
| Loss | 3–3 | Romania F11, Oradea | Futures | Clay | Ilie-Aurelian Giurgiu | Attila Balázs György Balázs | 2–6, 2–6 | |
| Loss | 3–4 | Italy F23, Bolzano | Futures | Clay | Antal van der Duim | Manuel Jorquera Leonardo Tavares | 7–6(7–2), 3–6, 5–10 | |
| Win | 4–4 | Romania F14, Arad | Futures | Clay | Vasek Pospisil | Andrei Mlendea Jiří Školoudík | 6–3, 6–4 | |
| Loss | 4–5 | Romania F15, Brașov | Futures | Clay | Vasek Pospisil | C C-Rodriguez Gerard Granollers-Pujol | 5–7, 7–6(7–2), 10–12 | |
| Win | 5–5 | Guatemala F1, Guatemala City | Futures | Hard | Iván Endara | James Ludlow Ruben Gonzales | 7–5, 6–3 | |
| Loss | 5–6 | Italy F30, Calabria | Futures | Clay | Giuseppe Faraone | Andrea Arnaboldi Gianluca Naso | 4–6, 4–6 | |
| Win | 6–6 | Germany F2, Stuttgart | Futures | Hard | Simon Stadler | Kevin Krawietz Marcel Zimmermann | 6–1, 6–2 | |
| Loss | 6–7 | Romania F2, Bucharest | Futures | Clay | Victor Crivoi | Florin Mergea Andrei Dăescu | 6–7(4–7), 2–6 | |
| Win | 7–7 | Romania F3, Bacău | Futures | Clay | Victor Crivoi | Harri Heliövaara Timo Nieminen | 6–3, 6–4 | |
| Win | 1–0 | Brașov, Romania | Challenger | Clay | Victor Crivoi | Andrei Ciumac Aleksandr Nedovyesov | 6–7(8–10), 6–4, 12–10 | |
| Loss | 1–1 | Binghamton, United States | Challenger | Hard | Sergiy Stakhovsky | Daniel Cox Daniel Smethurst | 7–6(7–3), 2–6, 6–10 | |
| Loss | 1–2 | Sibiu, Romania | Challenger | Clay | Alexandru-Daniel Carpen | Potito Starace Adrian Ungur | 5–7, 2–6 | |
| Loss | 1–3 | Istanbul, Turkey | Challenger | Hard | Marco Chiudinelli | Sadio Doumbia Calvin Hemery | 4–6, 3–6 | |
| Win | 2–3 | İzmir, Turkey | Challenger | Hard | Marco Chiudinelli | Sadio Doumbia Calvin Hemery | 6–4, 6–4 |
| Season | 2018 | 2019 | Total |
| Wins | 2 | 0 | 2 |
| 2018 | |||||||
| 1. | Marin Čilić | 6 | Swiss Indoors, Switzerland | Hard (i) | 2R | 7–5, 7–6(7–2) | 93 |
| 2. | Alexander Zverev | 5 | Swiss Indoors, Switzerland | Hard (i) | SF | 6–3, 6–7(6–8), 6–4 | 93 |
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