2008: ATP debut

Middelkoop made his ATP Tour doubles debut at the 2008 ABN AMRO World Tennis Tournament held on hard courts in Rotterdam, Netherlands. He was granted a direct acceptance into the doubles draw alongside compatriot Jesse Huta Galung, however they would be defeated in the first round by second seeds and eventual semi-finalists Julian Knowle and Simon Aspelin in straight sets 3–6, 5–7.

2016–2017: First Major quarterfinal, Maiden title & three more ATP 250 titles

Middelkoop won his maiden ATP tour doubles title at the 2016 Sofia Open on indoor hard courts in Bulgaria, partnering compatriot Wesley Koolhof. The pair defeated Adil Shamasdin and Philipp Oswald in a third set tie-breaker 5–7, 7–6^(11–9), [10–6] in the championship match to capture the title.

2018–2020: Five more titles & ten finals, Top 30 career-high

2021: Second Major quarterfinal, Masters semifinal, Three titles, top 30 return

2021 was the most successful year after 2018 on the ATP tour in Middelkoop's professional career. With his partner Marcelo Arévalo, the pair reached the quarterfinals of the 2021 Australian Open and the semifinals of the 2021 Italian Open (tennis) defeating home favorites Fognini/Musetti in the round of 16 and Dutch pair Koolhof/Rojer in the quarterfinals. As a result, he returned to the top 40 in the doubles rankings.

At the 2021 Winston-Salem Open, he won his tenth title partnering Arévalo when they defeated Ivan Dodig and Austin Krajicek in the final.^[2] As a result, he reentered the top 30 at a new career-high of World No. 28 on 30 August 2021.

2022: First ATP 500 title, French Open semifinalist, top 25 debut, 30th final

At the 2022 ABN AMRO World Tennis Tournament he won his first ATP 500 title with Robin Haase.^[3] As a result he reached a career-high ranking of World No. 26 on 14 February 2022.

At the 2022 French Open he reached the semifinals for the first time at a Grand Slam in his career partnering Rohan Bopanna defeating en route the second seeds, former World No. 1 pair and 2021 Wimbledon champions Nikola Mektić/Mate Pavić.^[4][5][6]

He reached a career-high in the top 25 on 27 June 2022 at the start of the 2022 Wimbledon Championships.

2023: Top 20 debut and ATP title, second French Open semifinal in doubles

He reached the top 20 in doubles at world No. 19 on 30 January 2023.

At the 2023 Open Sud de France reached his thirty first doubles final partnering compatriot Haase.^[7] He won his fourteenth title defeating Maxime Cressy/Albano Olivetti.^[8]

At the 2023 French Open he reached back-to-back semifinals partnering Andreas Mies this time.

Doubles: 32 (14 titles, 18 runner-ups)

More information Result, W–L ...

Result	W–L	Date	Tournament	Tier	Surface	Partner	Opponents	Score
Win	1–0	Feb 2016	Sofia Open, Bulgaria	250 Series	Hard (i)	Wesley Koolhof	Philipp Oswald Adil Shamasdin	5–7, 7–6(11–9), [10–6]
Win	2–0	Jul 2016	Austrian Open, Austria	250 Series	Clay	Wesley Koolhof	Dennis Novak Dominic Thiem	2–6, 6–3, [11–9]
Win	3–0	Jan 2017	Sydney International, Australia	250 Series	Hard	Wesley Koolhof	Jamie Murray Bruno Soares	6–3, 7–5
Loss	3–1	Feb 2017	Rotterdam Open, Netherlands	500 Series	Hard (i)	Wesley Koolhof	Ivan Dodig Marcel Granollers	6–7(5–7), 3–6
Loss	3–2	Jul 2017	Swedish Open, Sweden	250 Series	Clay	Sander Arends	Julian Knowle Philipp Petzschner	2–6, 6–3, [7–10]
Win	4–2	Sep 2017	St. Petersburg Open, Russia	250 Series	Hard (i)	Roman Jebavý	Julio Peralta Horacio Zeballos	6–4, 6–4
Win	5–2	Jan 2018	Maharashtra Open, India	250 Series	Hard	Robin Haase	Pierre-Hugues Herbert Gilles Simon	7–6(7–5), 7–6(7–5)
Win	6–2	Feb 2018	Sofia Open, Bulgaria (2)	250 Series	Hard (i)	Robin Haase	Nikola Mektić Alexander Peya	5–7, 6–4, [10–4]
Loss	6–3	Apr 2018	Hungarian Open, Hungary	250 Series	Clay	Andrés Molteni	Dominic Inglot Franko Škugor	7–6(10–8), 1–6, [8–10]
Loss	6–4	May 2018	Lyon Open, France	250 Series	Clay	Roman Jebavý	Nick Kyrgios Jack Sock	5–7, 6–2, [9–11]
Loss	6–5	Jun 2018	Antalya Open, Turkey	250 Series	Grass	Sander Arends	Marcelo Demoliner Santiago González	5–7, 7–6(8–6), [8–10]
Win	7–5	Jul 2018	Croatia Open Umag, Croatia	250 Series	Clay	Robin Haase	Roman Jebavý Jiří Veselý	6–4, 6–4
Loss	7–6	Sep 2018	St. Petersburg Open, Russia	250 Series	Hard (i)	Roman Jebavý	Matteo Berrettini Fabio Fognini	6–7(6–8), 6–7(4–7)
Loss	7–7	Jan 2019	Qatar Open, Qatar	250 Series	Hard	Robin Haase	David Goffin Pierre-Hugues Herbert	7–5, 4–6, [4–10]
Loss	7–8	Feb 2019	Open 13, France	250 Series	Hard (i)	Ben McLachlan	Jérémy Chardy Fabrice Martin	3–6, 7–6(7–4), [3–10]
Loss	7–9	Apr 2019	Grand Prix Hassan II, Morocco	250 Series	Clay	Frederik Nielsen	Jürgen Melzer Franko Škugor	4–6, 6–7(6–8)
Loss	7–10	Sep 2019	Zhuhai Championships, China	250 Series	Hard	Marcelo Demoliner	Sander Gillé Joran Vliegen	6–7(2–7), 6–7(4–7)
Win	8–10	Oct 2019	Kremlin Cup, Russia	250 Series	Hard (i)	Marcelo Demoliner	Simone Bolelli Andrés Molteni	6–1, 6–2
Win	9–10	Feb 2020	Córdoba Open, Argentina	250 Series	Clay	Marcelo Demoliner	Leonardo Mayer Andrés Molteni	6-3, 7-6(7–4)
Loss	9–11	Oct 2020	St. Petersburg Open, Russia	500 Series	Hard (i)	Marcelo Demoliner	Jürgen Melzer Édouard Roger-Vasselin	2–6, 6–7(4–7)
Loss	9–12	Oct 2020	European Open, Belgium	250 Series	Hard (i)	Rohan Bopanna	John Peers Michael Venus	3–6, 4–6
Loss	9–13	Jul 2021	Austrian Open Kitzbühel, Austria	250 Series	Clay	Roman Jebavý	Alexander Erler Lucas Miedler	5–7, 6–7(5–7)
Win	10–13	Aug 2021	Winston-Salem Open, United States	250 Series	Hard	Marcelo Arévalo	Ivan Dodig Austin Krajicek	6–7(5–7), 7–5, [10–6]
Win	11-13	Oct 2021	Kremlin Cup, Russia	250 Series	Hard (i)	Harri Heliövaara	Tomislav Brkić Nikola Ćaćić	7-5, 4–6, [11–9]
Win	12–13	Feb 2022	Rotterdam Open, Netherlands	500 Series	Hard (i)	Robin Haase	Lloyd Harris Tim Pütz	4–6, 7–6(7–5), [10–5]
Loss	12–14	May 2022	Geneva Open, Switzerland	250 Series	Clay	Pablo Andújar	Nikola Mektić Mate Pavić	6–2, 2–6, [3–10]
Loss	12–15	Jun 2022	Eastbourne International, United Kingdom	250 Series	Grass	Luke Saville	Nikola Mektić Mate Pavić	4–6, 2–6
Loss	12–16	Jul 2022	Hamburg European Open, Germany	500 Series	Clay	Rohan Bopanna	Lloyd Glasspool Harri Heliövaara	2–6, 4–6
Win	13–16	Oct 2022	Tel Aviv Open, Israel	250 Series	Hard (i)	Rohan Bopanna	Santiago González Andrés Molteni	6–2, 6–4
Loss	13–17	Oct 2022	European Open, Belgium	250 Series	Hard (i)	Rohan Bopanna	Tallon Griekspoor Botic van de Zandschulp	6–3, 3–6, [5–10]
Win	14–17	Feb 2023	Open Sud de France, France	250 Series	Hard (i)	Robin Haase	Maxime Cressy Albano Olivetti	7–6(7–4), 4–6, [10–6]
Loss	14–18	Jul 2023	Swiss Open Gstaad, Switzerland	250 Series	Clay	Marcelo Demoliner	Dominic Stricker Stan Wawrinka	6-7(8–10), 2–6

Close

Singles: 28 (15–13)

More information Result, W–L ...

Result	W–L	Date	Tournament	Tier	Surface	Opponent	Score
Loss	0–1	Oct 2004	Rwanda F1, Kigali	Futures	Clay	Andrew Anderson	3–6, 6–7(3–7)
Loss	0–2	Jun 2006	Netherlands F1, Meppel	Futures	Clay	Boy Westerhof	4–6, 6–7(5–7)
Win	1–2	Sep 2006	Netherlands F6, Enschede	Futures	Clay	Boy Westerhof	7–5, 6–7(2–7), 6–3
Win	2–2	Jan 2007	France F1, Deauville	Futures	Clay	Rabie Chaki	6–3, 3–6, 7–6(7–0)
Win	3–2	Feb 2007	Spain F6, Cartagena	Futures	Clay	Adrián Menéndez Maceiras	7–5, 4–6, 6–0
Loss	3–3	Aug 2007	Netherlands F4, Vlaardingen	Futures	Clay	Nick van der Meer	6–3, 3–6, 4–6
Loss	3–4	Sep 2007	Bosnia & Herzegovina F5, Mostar	Futures	Clay	Vjekoslav Skenderovic	2–6, 4–6
Win	4–4	Nov 2007	Rwanda F1, Kigali	Futures	Clay	Gvidas Sabeckis	7–5, 6–3
Win	5–4	Nov 2007	Uganda F1, Kampala	Futures	Clay	Komlavi Loglo	6–3, 7–5
Win	6–4	Dec 2007	Sudan F1, Khartoum	Futures	Clay	Sherif Sabry	6–3, 6–2
Win	7–4	Dec 2007	Sudan F2, Khartoum	Futures	Clay	Predrag Rusevski	walkover
Win	8–4	Mar 2008	Ivory Coast F2, Abidjan	Futures	Hard	Jérémy Blandin	6–7(4–7), 6–4, 6–1
Win	9–4	Mar 2010	Switzerland F2, Wetzikon	Futures	Carpet	Sandro Ehrat	6–3, 6–4
Loss	9–5	May 2010	Italy F10, Cesena	Futures	Clay	Frederik Nielsen	5–7, 7–6(7–5), 3–3 ret.
Win	10–5	Jun 2010	Netherlands F1, Apeldoorn	Futures	Clay	Mathieu Rodrigues	6–1, 6–4
Win	11–5	Sep 2010	Netherlands F6, Middelburg	Futures	Clay	Niels Desein	7–6(7–2), 6–2
Loss	11–6	Nov 2010	Dominican Republic F1, Santo Domingo	Futures	Hard	Víctor Estrella Burgos	1–6, 6–2, 1–6
Loss	11–7	Dec 2010	Dominican Republic F3, Santo Domingo	Futures	Hard	Víctor Estrella Burgos	4–6, 2–6
Win	12–7	May 2011	Italy F7, Vicenza	Futures	Clay	Juan-Martín Aranguren	7–5, 2–6, 6–4
Win	13–7	Jul 2011	Belgium F3, Knokke	Futures	Clay	Julien Obry	6–2, 6–3
Win	14–7	Jul 2012	Netherlands F4, Middelburg	Futures	Clay	Niels Desein	4–6, 6–2, 6–3
Loss	14–8	Jul 2012	Scheveningen, Netherlands	Challenger	Clay	Jerzy Janowicz	2–6, 2–6
Loss	14–9	Nov 2012	Thailand F4, Phuket	Futures	Hard	Miliaan Niesten	6–3, 3–6, 4–6
Loss	14–10	Jan 2013	Germany F3, Kaarst	Futures	Carpet	Miloslav Mečíř	2–6, 6–7(3–7)
Loss	14–11	Jun 2013	Netherlands F3, Breda	Futures	Clay	Thomas Schoorel	4–6, 4–6
Loss	14–12	Oct 2013	Turkey F42, Antalya	Futures	Hard	Adam El Mihdawy	1–2 ret.
Win	15–12	Oct 2014	Egypt F29, Sharm El Sheikh	Futures	Hard	Mohamed Safwat	7–5, 2–6, 6–3
Loss	15–13	Nov 2014	Morocco F4, Casablanca	Futures	Clay	Gerard Granollers Pujol	4–6, 2–6

Close

Doubles: 62 (37–25)

More information Result, W–L ...

Result	W–L	Date	Tournament	Tier	Surface	Partner	Opponents	Score
Loss	0–1	Sep 2003	Kenya F1, Mombasa	Futures	Hard	Bart Beks	W-P Meyer Wesley Whitehouse	3–6, 6–7(3–7)
Loss	0–2	Feb 2004	Canada F2, Edmonton	Futures	Hard	Paul Logtens	Ryan Haviland K.J. Hippensteel	3–6, 6–4, 6–7(5–7)
Win	1–2	Oct 2004	Rwanda F1, Kigali	Futures	Clay	Adam Thompson	Andrew Anderson Paul Anderson	6–2, 2–6, 6–4
Win	2–2	Nov 2004	Thailand F3, Pattaya	Futures	Hard	David Martin	Martin Slanar Herbert Wiltschnig	3–6, 6–4, 7–5
Win	3–2	Jun 2005	France F8, Blois	Futures	Clay	Bart Beks	Stéphane Robert E Carril-Caso	4–6, 6–2, 6–3
Win	4–2	Jul 2005	Valladolid, Spain	Challenger	Hard	Alexander Peya	Jasper Smit Stefan Wauters	7–6(9–7), 6–3
Loss	4–3	Oct 2005	Barcelona II, Spain	Challenger	Clay	Bart Beks	David Marrero Gabriel Trujillo Soler	4–6, 4–6
Loss	4–4	Jan 2006	Germany F4, Kaarst	Futures	Carpet	Bart Beks	Bastian Knittel Ralph Grambow	6–7(4–7), 6–7(5–7)
Loss	4–5	Mar 2006	Portugal F1, Faro	Futures	Hard	Bart Beks	Alessandro da Col Marcel Granollers	4–6, 6–3, 2–6
Loss	4–6	Aug 2006	Netherlands F4, Vlaardingen	Futures	Clay	Romano Frantzen	Martijn van Haasteren Michel Koning	5–7, 5–7
Win	5–6	Nov 2006	Tunisia F5, Monastir	Futures	Hard	Michel Koning	Adrian Cruciat A-V Gavrila	6–1, 6–1
Win	6–6	Apr 2007	Chiasso, Swsitzerland	Challenger	Clay	Bart Beks	Teodor-Dacian Crăciun Victor Crivoi	7–6(7–2), 7–5
Win	7–6	Sep 2007	Netherlands F5, Enschede	Futures	Clay	Michel Koning	Augustin Gensse Chris Wettengel	6–3, 6–2
Loss	7–7	Sep 2007	Bosnia & Herzegovina F5, Mostar	Futures	Clay	Francesco Piccari	Blaž Kavčič Jaroslav Pospíšil	6–4, 3–6, [5–10]
Win	8–7	Nov 2007	Rwanda F1, Kigali	Futures	Clay	Gvidas Sabeckis	Lawal Shehu Candy Idoko	7–6(9–7), 6–4
Win	9–7	Nov 2007	Uganda F1, Kampala	Futures	Clay	Gvidas Sabeckis	Komlavi Loglo Alexei Filenkov	6–1, 6–4
Loss	9–8	Mar 2008	Ivory Coast F1, Abidjan	Futures	Hard	Miliaan Niesten	Ilya Belyaev Sergei Krotiouk	6–2, 3–6, [5–10]
Loss	9–9	Jun 2008	Alessandria, Italy	Challenger	Clay	Melle van Gemerden	Flavio Cipolla Simone Vagnozzi	6–3, 1–6, [4–10]
Win	10–9	Jun 2008	Netherlands F3, Breda	Futures	Clay	Jesse Huta Galung	Niels Desein Jeroen Masson	3–6, 6–3, [10–8]
Loss	10–10	Jul 2008	Scheveningen, Netherlands	Challenger	Clay	Melle van Gemerden	Rameez Junaid Philipp Marx	7–5, 2–6, [6–10]
Loss	10–11	Jul 2008	Rimini, Italy	Challenger	Clay	Cătălin-Ionuț Gârd	Leonardo Azzaro Marco Crugnola	1–6, 1–6
Loss	10–12	Sep 2008	Alphen aan den Rijn, Netherlands	Challenger	Clay	Bart Beks	Rameez Junaid Philipp Marx	3–6, 2–6
Loss	10–13	Jun 2009	Netherlands F3, Rotterdam	Futures	Clay	Miliaan Niesten	José Statham Rylan Rizza	3–6, 6–7(4–7)
Win	11–13	Feb 2010	Azerbaijan F1, Baku	Futures	Hard	Petru-Alexandru Luncanu	Zhe Li Gong Mao-xin	6–7(7–9), 6–3, [12–10]
Win	12–13	Feb 2010	Azerbaijan F2, Baku	Futures	Hard	Antal van der Duim	Zhe Li Di Wu	7–6(10–8), 7–5
Win	13–13	Jun 2010	Netherlands F2, Alkmaar	Futures	Clay	Martijn van Haasteren	Timo Nieminen Michal Schmid	7–6(10–8), 6–4
Win	14–13	Jul 2010	Netherlands F4, Breda	Futures	Clay	Thomas Schoorel	Marcel Felder Aleksandr Agafonov	4–6, 6–3, [10–6]
Loss	14–14	Sep 2010	Rwanda F1, Kigali	Futures	Clay	Bogdan-Victor Leonte	Stanislav Vovk Alexei Filenkov	6–2, 4–6, [11–13]
Win	15–14	May 2011	Italy F7, Vicenza	Futures	Clay	Ivan Bjelica	Juan-Martín Aranguren Alejandro Fabbri	6–4, 6–4
Loss	15–15	Sep 2011	Alphen aan den Rijn, Netherlands	Challenger	Clay	Igor Sijsling	Thiemo de Bakker Antal van der Duim	4–6, 7–6(7–4), [6–10]
Loss	15–16	Sep 2011	Banja Luka, Bosnia & Herzegovina	Challenger	Clay	Jan Mertl	Rubén Ramírez Hidalgo Marco Crugnola	6–7(3–7), 6–3, [8–10]
Win	16–16	Jul 2012	Netherlands F3, Breda	Futures	Clay	Miliaan Niesten	Jan-Lennard Struff Patrick Pradella	6–2, 6–4
Win	17–16	Nov 2012	Thailand F4, Phuket	Futures	Hard	Miliaan Niesten	Mick Lescure Mehdi Bouras	6–3, 6–0
Loss	17–17	Sep 2013	Spain F32, Sevilla	Futures	Clay	Ramkumar Ramanathan	Eduard Esteve Lobato Oriol Roca Batalla	2–6, 3–6
Win	18–17	Oct 2013	Turkey F42, Antalya	Futures	Hard	Filip Horansky	Adrian Partl Danylo Kalenichenko	6–4, 6–3
Win	19–17	Jul 2014	Scheveningen, Netherlands	Challenger	Clay	Boy Westerhof	Martin Fischer Jesse Huta Galung	6–4, 3–6, [10–6]
Win	20–17	Aug 2014	Netherlands F6, Rotterdam	Futures	Clay	Stephan Fransen	Marc Rath Nicolas Reissig	6–1, 6–2
Win	21–17	Oct 2014	Egypt F28, Sharm El Sheikh	Futures	Hard	Mohamed Safwat	Sherif Sabry Libor Salaba	6–3, 6–4
Win	22–17	Oct 2014	Egypt F29, Sharm El Sheikh	Futures	Hard	Mohamed Safwat	Jan Zieliński Libor Salaba	7–6(7–1), 6–3
Win	23–17	Nov 2014	Morocco F4, Casablanca	Futures	Clay	Dušan Lojda	Yassine Idmbarek Mehdi Jdi	6–1, 6–2
Loss	23–18	Jan 2015	Germany F3, Kaarst	Futures	Carpet	Wesley Koolhof	Sander Arends Adam Majchrowicz	3–6, 4–6
Win	24–18	Feb 2015	France F3, Feucherolles	Futures	Hard	Wesley Koolhof	Maxime Authom Yannick Mertens	6–3, 6–4
Win	25–18	Feb 2015	Glasgow, United Kingdom	Challenger	Hard	Wesley Koolhof	Sergey Bubka Aleksandr Nedovyesov	6–1, 6–4
Loss	25–19	Apr 2015	Le Gosier, Guadeloupe	Challenger	Hard	Wesley Koolhof	Antal van der Duim James Cerretani	1–6, 3–6
Win	26–19	May 2015	Turin, Italy	Challenger	Clay	Wesley Koolhof	Dino Marcan Antonio Šančić	4–6, 6–3, [10–5]
Win	27–19	Jul 2015	Marburg, Germany	Challenger	Clay	Wesley Koolhof	Tobias Kamke Simon Stadler	6–1, 7–5
Loss	27–20	Aug 2015	Liberec, Czech Republic	Challenger	Clay	Wesley Koolhof	Hans Podlipnik Castillo Andrej Martin	5–7, 7–6(7–3), [5–10]
Win	28–20	Aug 2015	Prague, Czech Republic	Challenger	Clay	Wesley Koolhof	Sergey Betov Mikhail Elgin	6–4, 3–6, [10–7]
Loss	28–21	Aug 2015	Meerbusch, Germany	Challenger	Clay	Wesley Koolhof	Rameez Junaid Dustin Brown	4–6, 5–7
Win	29–21	Aug 2015	Netherlands F6, Rotterdam	Futures	Clay	Wesley Koolhof	Oscar Otte Matthias Wunner	6–3, 6–3
Win	30–21	Sep 2015	Seville, Spain	Challenger	Clay	Wesley Koolhof	Marco Bortolotti Kamil Majchrzak	7–6(7–5), 6–4
Win	31–21	Sep 2015	Trnava, Slovakia	Challenger	Clay	Wesley Koolhof	Kamil Majchrzak Stéphane Robert	6–4, 6–2
Loss	31–22	Oct 2015	Rennes, France	Challenger	Hard	Wesley Koolhof	Andrea Arnaboldi Antonio Šančić	4–6, 6–2, [12–14]
Win	32–22	Oct 2015	Brest, France	Challenger	Hard	Wesley Koolhof	Ken Skupski Neal Skupski	3–6, 6–4, [10–6]
Win	33–22	Jan 2016	Bangkok, Thailand	Challenger	Hard	Wesley Koolhof	Gero Kretschmer Alexander Satschko	6–3, 7–6(7–1)
Win	34–22	Jun 2016	Ilkley, United Kingdom	Challenger	Grass	Wesley Koolhof	Marcelo Demoliner Aisam Qureshi	7–6(7–5), 0–6, [10–8]
Win	35–22	Jul 2016	Scheveningen, Netherlands	Challenger	Clay	Wesley Koolhof	Tallon Griekspoor Tim van Rijthoven	6–1, 3–6, [13–11]
Loss	35–23	Nov 2016	Brescia, Italy	Challenger	Hard	Wesley Koolhof	Alexander Kudryavtsev Mikhail Elgin	6–7(4–7), 3–6
Win	36–23	Nov 2016	Andria, Italy	Challenger	Hard	Wesley Koolhof	Roman Jebavý Zdeněk Kolář	6–3, 6–3
Win	37–23	May 2017	Aix En Provence, France	Challenger	Clay	Wesley Koolhof	Andre Begemann Jérémy Chardy	2–6, 6–4, [16–14]
Loss	37–24	Aug 2017	Cordenons, Italy	Challenger	Clay	Igor Zelenay	Roman Jebavý Zdeněk Kolář	2–6, 3–6
Loss	37–25	Sep 2019	Szczecin, Poland	Challenger	Clay	Hans Podlipnik Castillo	Andrés Molteni Guido Andreozzi	4–6, 3–6

Close

Singles

Doubles

Current through the 2022 Davis Cup.

Mixed doubles