- The team continued with aero data collection and power unit work on Wednesday, completing a long run programme in the morning before moving to single lap runs in the afternoon to allow Nikita to gain experience on the three softest tyre compounds
- Mercedes-Benz Power Units completed a total of 1,946 km today
"Today was incredible. Being a part of this team, even just for this day was very special for me. It’s every young driver’s dream to drive a car like this and today mine came true, so I’m really happy. Importantly it was a successful day on track too, we gathered most of the data we set out to collect, we didn’t encounter any problems and from my side I felt I could deliver consistently throughout the day – which is important for the team. In the afternoon we were competitive on the performance runs and the car felt great. Everyone in the team is working so hard and you can feel that when you sit in this car."
"It’s been another successful day here in Barcelona and we managed to complete all of the programme we had planned. We spent the first three quarters of the day focused on aerodynamic and Power Unit development testing, before switching to one-lap performance runs, working through the different specifications of the tyre with Nikita. He did a really superb job today, just as we expected he would."
| Pos | Driver | Team | Time | Laps |
| 1 | Nikita Mazepin (21) | Mercedes-AMG Petronas Motorsport | 1:15.775 | 128 |
| 2 | Alex Albon (23) | Toro Rosso | 1:17.079 | 110 |
| 3 | Antonio Fuoco (32) | Ferrari | 1:17.284 | 120 |
| 4 | Charles Leclerc (16) | Ferrari (Pirelli) | 1:17.349 | 127 |
| 5 | Kimi Räikkönen (7) | Alfa Romeo | 1:17.393 | 110 |
| 6 | Jack Aitken (45) | Renault | 1:17.621 | 75 |
| 7 | Kevin Magnussen (20) | Haas | 1:18.101 | 106 |
| 8 | Nick Yelloly (34) | Racing Point | 1:18.212 | 83 |
| 9 | Nicholas Latifi (40) | Williams | 1:18.573 | 88 |
| 10 | Dan Ticktum (24) | Red Bull | 1:19.458 | 79 |
| 11 | Oliver Turvey (48) | McLaren | 1:20.712 | 52 |
| 12 | Lance Stroll (18) | Racing Point (Pirelli) | 1:20.745 | 119 |
| 13 | Sergio Sette Camara (47) | McLaren | 1:21.565 | 19 |
