Junior and amateur years

Cosnefroy was born into a family passionate about cycling. His grandfather was the organizer of a race in the English Channel, while his father often took him to see bike races during his youth. He first started competing at the age of 8 with the Union Concorde Bricquebetaise.^[5] In 2011, he joined the Pôle Espoir de Caen, where he stayed for three years.^[6] He took his first victory at the age of 16 in the Prix Louis-Cosnefroy, a race held as a tribute to his great-great-grandfather Louis Cosnefroy.^[7] However, during his years in the junior category, Cosnefroy saw little success. In 2014, he moved up to the under-23 category, joining team Bricquebec Cotentin. The following year he joined Chambéry CF, the development team of AG2R La Mondiale after hitchhiking along the nine-hour drive to apply.^[8] This year, he achieved modest success in amateur and under-23 races. In 2016, he began to obtain more results, notably placing second by half a wheel length to Valentin Madouas at the national amateur road race championships, and second to Paul Ourselin in the under-23 national championship.^[9][10] He joined AG2R La Mondiale as a stagiaire in August, placing 4th in the road race at the UEC European Under-23 Road Championships.^[11]

The 2017 season was a major turning point in Cosnefory's career, and was his final year competing as an amateur. He took his first elite category win in May: stage 2 of the Rhône-Alpes Isère Tour, holding off the peloton for almost 160 kilometers.^[12] The same month, he placed sixth in the Grand Prix de Plumelec-Morbihan, his first top ten in a 1.1 or higher category race.

Professional career

Cosnefroy turned professional in August 2017 with UCI WorldTeam AG2R La Mondiale. Five days after joining the team, he won the silver medal in the road race at the UEC European Under-23 Road Championships. His success continued, winning the Grand Prix d'Isbergues in September, followed by the under-23 road race at the UCI Road World Championships five days later.

Cosnefroy completed his first full professional season in 2018, notably placing third in Paris–Tours and ninth in the Bretagne Classic Ouest-France, his first top ten in a UCI World Tour race.^[13]

Cosnefroy took five victories in 2019, all in France: the overall classification and third stage of the Tour du Limousin as well as the one-day races Grand Prix de Plumelec-Morbihan, Paris–Camembert and Polynormande. In July 2019, he was named in the startlist for the 2019 Tour de France, which was his first Grand Tour. He placed 113th overall.^[14]

At the beginning of 2020, he won the Grand Prix La Marseillaise and the Étoile de Bessèges before the season stopped due to the Covid-19 pandemic.^[15] As soon as racing resumed, he won the fourth and final stage of the Route d'Occitanie ahead of Bauke Mollema, Thibaut Pinot and Egan Bernal.^[16] He was selected for the French team for the UEC European Road Championships held in Plouay, where he finished tenth in the road race.^[17] In the 2020 Tour de France, he led the mountains classification and wore the polka dot jersey for 15 consecutive stages; he ultimately finished sixth in the final classification standings. He ended the season strongly, placing second to Marc Hirschi in the La Flèche Wallonne, as well as third in De Brabantse Pijl and second in Paris–Tours.

On 22 May 2021, he won the Tour du Finistère and three months later he won his first World Tour race: the Bretagne Classic ahead of Julian Alaphilippe and Mikkel Honoré.^[18] On 12 September, he won the bronze medal at the European Championships behind Sonny Colbrelli and Remco Evenepoel.^[19]

Grand Tour general classification results timeline

Grand Tour	2019	2020	2021	2022	2023
Giro d'Italia	—	—	—	—	—
Tour de France	113	116	107	91	101
Vuelta a España	—	—	—	—

Classics results timeline