2017–2019: Grand Slam debut

Müller made his ATP main draw debut at the 2017 French Open after receiving a wildcard to the singles main draw.^[2][3] He was defeated by Thiago Monteiro in the first round.

He qualified for the 2019 French Open but lost in the first round to Roberto Carballes Baena.

2021: First Grand Slam win, top 200 debut

At the 2021 Australian Open Müller won his first Grand Slam match as a lucky loser defeating Juan Ignacio Londero. As a result, he entered the top 200 at a career-high of World No. 194 on 22 February 2021.

2022: First Challenger title, top 150 debut

In June, Müller won his first Challenger tournament in Blois, France, defeating Nikola Milojevic. A month later, he made his top 150 debut 25 July 2022 at world No. 149.

2023: First ATP final, top 100 and Masters debuts

At the 2023 Qatar ExxonMobil Open in Doha, Müller as a qualifier reached his first ATP quarterfinal in his career, defeating Nikoloz Basilashvili and eighth seed Botic van de Zandschulp.^[4] He lost to Andy Murray.^[5]

At the 2023 Grand Prix Hassan II he reached a second quarterfinal defeating sixth seed Richard Gasquet and Francesco Passaro. Next he defeated top seed Lorenzo Musetti to reach his first ATP semifinal in a close to two hours match.^[6] He then faced Russian Pavel Kotov, defeating him also in two hours in straight sets to reach his first ATP final, before losing to Roberto Carballes Baena. As a result he secured a new carrier high singles ranking into the top 100 at world No. 96 on 10 April 2023.^[7] He made his Masters debut at the 2023 Italian Open (tennis) as a qualifier and recorded his first win defeating Kyle Edmund.

Müller reached a new career-high ranking of No. 82 on 26 June 2023 following his first title at a Challenger 125 level at the 2023 Emilia-Romagna Open in Montechiarugolo, Italy, defeating Francesco Maestrelli. He made his debut at Wimbledon, defeating compatriot Arthur Rinderknech in the first round for his second win in a Major. He then lost to top seed Carlos Alcaraz.^[8]

At the US Open, Müller faced second seed Novak Djokovic in the first round, losing in straight sets.^[9] He received a wildcard for the main draw of the 2023 Rolex Paris Masters.

Singles

Singles: 1 (1 runner-up)

Result	W–L	Date	Tournament	Tier	Surface	Opponent	Score
Loss	0–1	Apr 2023	Grand Prix Hassan II, Morocco	250 Series	Clay	Roberto Carballés Baena	6–4, 6–7(3–7), 2–6

Singles: 25 (9–16)

Result	W–L	Date	Tournament	Tier	Surface	Opponent	Score
Loss	0–1	Nov 2015	Tunisia F32, El Kantaoui	Futures	Hard	Nikola Milojević	2–6, 3–6
Loss	0–2	Mar 2016	Egypt F8, Sharm El Sheikh	Futures	Hard	Marko Tepavac	6–7(3–7), 1–6
Loss	0–3	May 2016	Algeria F1, Oran	Futures	Clay	Sadio Doumbia	6–4, 4–6, 4–6
Loss	0–4	Jun 2016	Macedonia F1, Skopje	Futures	Clay	Danilo Petrović	3–6, 6–4, 6–7(6–8)
Win	1–4	Jul 2016	Macedonia F2, Skopje	Futures	Clay	Dimitar Grabul	6–2, 6–4
Loss	1–5	Aug 2016	Morocco F6, Tanger	Futures	Clay	Maxime Hamou	3–6, 6–4, 2–6
Loss	1–6	Oct 2016	Croatia F9, Bol	Futures	Clay	Riccardo Bellotti	4–6, 1–6
Loss	1–7	Nov 2016	Greece F8, Heraklion	Futures	Hard	Václav Šafránek	5–7, 4–6
Win	2–7	Nov 2016	Cyprus F2, Limassol	Futures	Hard	Lucas Miedler	6–2, 6–2
Loss	2–8	Dec 2016	Israel F17, Ramat Gan	Futures	Hard	David Guez	7–5, 5–7, 3–6
Loss	2–9	Feb 2017	Indonesia F3, Jakarta	Futures	Hard	Sebastian Fanselow	1–6, 3–6
Loss	2–10	May 2017	France F10, Grasse	Futures	Clay	Corentin Moutet	4–6, 3–6
Win	3–10	Jul 2017	Poland F3, Mrągowo	Futures	Clay	Markus Eriksson	6–3, 0–6, 6–3
Win	4–10	Jul 2017	France F16, Uriage	Futures	Clay	Corentin Denolly	5–7, 7–6(7–1), 6–4
Win	5–10	Oct 2017	Tunisia F32, Hammamet	Futures	Clay	Guillermo Olaso	4–6, 6–3, 6–3
Loss	5–11	Mar 2018	Tunisia F8, Jerba	Futures	Hard	Moez Echargui	6–7(5–7), 6–2, 1–6
Loss	5–12	Sep 2018	Lebanon F1, Jounieh	Futures	Clay	Jordi Samper Montaña	3–6, 4–6
Win	6–12	Oct 2018	Lebanon F2, Jounieh	Futures	Clay	Fabien Reboul	6–7(2–7), 6–3, 6–4
Loss	6–13	Dec 2018	Tunisia F42, Monastir	Futures	Hard	Aslan Karatsev	4–6, 6–4, 1–6
Loss	6–14	Sep 2019	Glasgow, Great Britain	Challenger	Hard (i)	Emil Ruusuvuori	3–6, 1–6
Loss	6-15	Oct 2019	M25 Tavira, Portugal	World Tennis Tour	Hard	Frederico Ferreira Silva	2–6, 1–6
Win	7-15	Nov 2019	M25 Monastir, Tunisia	World Tennis Tour	Hard	Petros Chrysochos	3–6, 7–6 (7-5), 6–2
Win	8–15	Jun 2022	Blois, France	Challenger	Clay	Nikola Milojevic	7–6(7-3), 6–1
Loss	8–16	Feb 2023	Waco, Texas	Challenger	Hard	Aleksandar Kovacevic	3–6, 6–4, 2–6
Win	9–16	Jun 2023	Montechiarugolo, Italy	Challenger	Clay	Francesco Maestrelli	6–1, 6–4

Doubles: 16 (8–8)

Result	W–L	Date	Tournament	Tier	Surface	Partner	Opponents	Score
Loss	0–1	Oct 2015	Greece F8, Heraklion	Futures	Hard	Corentin Denolly	Lloyd Glasspool Joshua Ward-Hibbert	w/o
Win	1–1	Jan 2016	France F1, Bagnoles-de-l'Orne	Futures	Clay (i)	Corentin Denolly	Benjamin Bonzi Grégoire Jacq	2–6, 6–1, [10–6]
Win	2–1	May 2016	Algeria F1, Oran	Futures	Clay	Fabien Reboul	Adria Mas Mascolo Pol Toledo Bagué	6–4, 6–4
Win	3–1	May 2016	Algeria F2, Algiers	Futures	Clay	Grégoire Jacq	Jordi Muñoz Abreu Fabien Reboul	6–4, 6–3
Loss	3–2	Jul 2016	Italy F20, Casinalbo	Futures	Clay	Pirmin Hänle	Riccardo Balzerani Enrico Dalla Valle	3–6, 3–6
Loss	3–3	Aug 2016	Morocco F5, Tanger	Futures	Clay	Gianni Mina	Sander Gillé Antoine Hoang	4–6, 6–7(7–9)
Loss	3–4	Aug 2016	Morocco F6, Tanger	Futures	Clay	Gianni Mina	Felipe Cunha Silva Julian Ocleppo	3–6, 3–6
Loss	3–5	Nov 2016	Greece F8, Heraklion	Futures	Hard	Florent Diep	Adrian Bodmer Jakob Sude	2–6, 1–6
Loss	3–6	Dec 2016	Cyprus F3, Larnaca	Futures	Hard	Markos Kalovelonis	Lucas Miedler Maximilian Neuchrist	3–6, 6–1, [5–10]
Win	4–6	Jan 2017	Egypt F1, Sharm El Sheikh	Futures	Hard	Antoine Escoffier	Adrian Bodmer Jakob Sude	6–2, 3–6, [11–9]
Win	5–6	Jul 2017	Belgium F4, Lasne	Futures	Clay	Corentin Denolly	Maxence Brovillé Clément Tabur	6–1, 6–3
Win	6–6	Jul 2017	France F16, Uriage	Futures	Clay	Corentin Denolly	Antoine Bellier Johan Sébastien Tatlot	6–3, 7–5
Loss	6–7	May 2018	France F9, Grasse	Futures	Clay	Corentin Denolly	Hugo Gaston Clément Tabur	2–6, 4–6
Win	7–7	Jun 2019	Blois, France	Challenger	Clay	Corentin Denolly	Sergio Galdós Andreas Siljeström	7–5, 6–7(5–7), [10–6]
Loss	7–8	Feb 2022	Bangalore, India	Challenger	Hard	Hugo Grenier	Saketh Myneni Ramkumar Ramanathan	3-6, 2-6
Win	8–8	Apr 2022	Sanremo, Italy	Challenger	Clay	Geoffrey Blancaneaux	Flavio Cobolli Matteo Gigante	4–6, 6–3, [11–9]