2019: Juniors A member of Ninon Tennis Club in
Pornichet, he was European U18 champion in both singles and doubles in 2019, playing doubles alongside
Harold Mayot.
2022: First ITF title In May, Royer won his first
ITF title in
Ulcinj, Montenegro, defeating Samuel Vincent Ruggeri in the final.
2024: Maiden Challenger title, Top 200 In April, he defeated
Dennis Novak at the ITF Tour event in
Oeiras, Portugal to ensure a ranking high enough to make his debut in senior qualifying for a Grand Slam at the
2024 French Open. In the men's qualifying at Roland Garros in May 2024 he won his first round match against
Dmitry Popko. In the second round of qualifying he lost in the deciding set to
Thiago Monteiro of Brazil. In May, Royer reached his first
Challenger final in
Tunis, losing to
Oriol Roca Batalla in the final. In the first round of qualifying at the
2024 Wimbledon Championships he lost to eventual qualifier
Li Tu of Australia. Competing in the qualifying at the
2024 US Open he defeated
Hugo Dellien of Bolivia and local player
Ethan Quinn before losing to
Gabriel Diallo of Canada in the final qualifying round. In September, Royer won his maiden
Challenger title in
Sibiu, Romania, defeating compatriot
Luka Pavlovic in straight sets in the final.
2025: Major debut & first win, ATP final, top 60 In February, Royer won back-to-back
Challenger 100 titles at the two editions of the
Rwanda Challenger, defeating
Andrej Martin in the final, and the following week at the
Rwanda II Challenger, defeating
Guy Den Ouden in the final. As a result, Royer reached the top 125 at world No. 121 on 17 March 2025. He reached his third straight final at the
2025 Zadar Open, where he lost to
Borna Ćorić, but despite the loss reached the top 115 in the ATP rankings on 24 March 2025. In May, Royer received a main draw wildcard for the
2025 French Open, marking his Grand Slam debut. He lost to
Daniel Elahi Galán in the first round. In June, Royer reached the final at the
2025 Bratislava Open. He lost to
Dino Prižmić in the final. In July, Royer made his
Wimbledon debut, reaching the main draw as a qualifier after defeating fellow countryman
Titouan Droguet in the final round. In the main draw, Royer upset 26th seed
Stefanos Tsitsipas recording his first Grand Slam win. He lost in the second round to fellow countryman
Adrian Mannarino. Royer also made his
ATP Tour debut as a qualifier at the
Canadian Open. He lost in the first round to
Nicolas Arseneault. In August, Royer earned his first
Masters 1000 win at the
2025 Cincinnati Open as a qualifier, defeating
Sebastian Ofner in the first round. He lost in three sets to 14th seed
Karen Khachanov in the second round. In August, Royer made his
US Open debut after receiving a wildcard into the main draw. He recorded his second major win by defeating
Bu Yunchaokete in the first round. At the
2025 Hangzhou Open Royer qualified for the main draw and reached his first
ATP final upsetting three seeds en route: top seed
Andrey Rublev, recording his first top-20 win, seventh seed
Learner Tien and fourth seed
Corentin Moutet. As a result he reached a new career-high of No. 76 in the singles rankings on 22 September 2025. He lost to
Alexander Bublik in the final. ==Performance timeline==