O terceiro treino livre para o GP da França,  no Circuito de Paul Ricard, em Le Castellet, oitava etapa da temporada, teve apenas cinco minutos de pista seca. O finlandês Valteri Bottas (Mercedes) marcou o melhor tempo, 1m33s666.                                                                                                              Tempos:
1 – Valtteri Bottas (Mercedes) – 1’33’’666 – 3 voltas
2 – Carolos Sainz (Renault) – 1’34’’953 – 3
3 – Charles Leclerc (Sauber-Ferrari) – 1’35’’012 – 5
4 – Fernando Alonso (McLaren-Renault) – 1’36’’365 – 4
5 – Sebastian Vettel (Ferrari) – 1’36’’756 – 5
6 – Stoffel Vandoorne (McLaren-Renault) – 1’37’’547 – 4
7 – Pierre Gasly (Toro Rosso-Honda) – 1’38’’317 – 5
8 – Marcus Ericsson (Sauber-Ferrari) – 1’38’’450 – 3
9 – Sergio Perez (Force India-Mercedes) – 1’39’’641 – 4
10 – Daniel Ricciardo (Red Bull-Renault) – 1’39’’738 – 3
11 – Esteban Ocon (Force India-Mercedes) – 1’40’’087 – 4
12 – Lewis Hamilton (Mercedes) – 1’40’’743 – 3
13 – Kimi Raikkonen (Ferrari) – 1’49’’711 – 3
14 – Lance Stroll (Williams-Mercedes) – 2’02’’399 – 4
15 – Sergey Sirotkin (Williams-Mercedes) – 2’04’’093 – 5
16 – Kevin Magnussen (Haas-Ferrari) – sem tempo – 1
17 – Brendon Hartley (Toro Rosso-Honda) – sem tempo – 3
18 – Romain Grosjean (Haas-Ferrari) – sem tempo – 1
19 – Nico Hulkenberg (Renault) – sem tempo – 2
20 – Max Verstappen (Red Bull-Renault) – sem tempo – 3