Julian Marc Jeanvier (born 31 March 1992) is a professional footballer who plays as a central defender for Süper Lig club Kayserispor and the Guinea national team.

[7] Behind Simon Kjær, Marko Baša, David Rozehnal and Adama Soumaoro in the central defensive pecking order,[7] he was completely out of favour with manager René Girard,[5] who had replaced Rudi Garcia soon after Jeanvier's arrival at the Stade Pierre-Mauroy.

[5] On 30 July 2018, Jeanvier moved to England to join Championship club Brentford on a four-year contract, with the option of a further year, for an undisclosed fee,[14] speculated to be £1.8 million.

[15] He scored a goal in each of his first two appearances for the club, which came in the early rounds of the EFL Cup,[16] but a foot injury suffered in October 2018 ruled him out for two months.

[17][18] The unavailability of Chris Mepham and new head coach Thomas Frank's deployment of three centre backs saw Jeanvier win a starting place on his return to fitness in December 2018 and he remained a near-ever present starter until the end of the 2018–19 season.

[5][19][20] Despite being behind Pontus Jansson and Ethan Pinnock in the pecking order when either was available,[21] Jeanvier made 27 appearances and scored one goal during the 2019–20 season,[22] but he did not feature during the Bees' unsuccessful playoff campaign.

[23] After the signing of Charlie Goode during the 2020 off-season saw Jeanvier demoted further down the pecking order, he joined Turkish Süper Lig club Kasımpaşa on loan for the duration of the 2020–21 season.

[30][31] On 10 April 2022, illness suffered by Pontus Jansson saw Jeanvier named in a matchday squad for the first time since the 2020 Championship play-off final and he remained an unused substitute during a 2–0 Premier League victory over West Ham United.

[5][41] Jeanvier was a member of the France U18 squad which finished runners-up at the 2010 Copa del Atlántico, but he failed to win a cap.