By-elections to the French National Assembly are held within three months after the invalidation of the election or resignation of a deputy. These by-elections were held during the 17th legislature of the French Fifth Republic.
| # | Outgoing MP | Party | End date of mandate | Constituency | Dates of the new election | Elected or re-elected MP | Party | Reason | ||
|---|---|---|---|---|---|---|---|---|---|---|
| 1 | Flavien Termet | RN | 5 October 2024 | Ardennes's 1st constituency | 1 and 8 December 2024 | Lionel Vuibert | Independent | Resignation for health reasons [1] | ||
| 2 | Hugo Prevost | LFI | 16 October 2024 | Isère's 1st constituency | 12 and 19 January 2025 | Camille Galliard-Minier | RE | Resignation after sexual assault allegations [2] | ||
| 3 | Stéphane Séjourné | RE | 30 November 2024 [3] | Hauts-de-Seine's 9th constituency | 2 and 9 February 2025 | Elisabeth de Maistre | LR | Nominated to the European Commission | ||