Grégoire Jacq (born 9 November 1992) is a French tennis player who specializes in doubles.

Next, the French duo Jacq/Guinard entered their home Slam, the 2024 French Open as alternates, and on their Major debut as a team, defeated 14th seeded American pair of Nathaniel Lammons and Jackson Withrow in the first round.

[6][7] He reached his first ATP final with Guinard at the 2024 Swedish Open defeating defending champions and top seeded pair of Aleksandr Nedovyesov and Gonzalo Escobar.

[9][10][11] The following week the pair reached their second ATP final at the 2024 Croatia Open Umag.

[12] At the 2025 Australian Open Jacq recorded his first win at the tournament, partnering Orlando Luz, over alternate pair Jeevan Nedunchezhiyan and Vijay Sundar Prashanth.