Kimi Antonelli, driving for Mercedes, claimed the fastest lap of the 2026-spec cars on the final day of Bahrain's pre-season testing, clocking a 1m32.803s lap. This time was over six tenths quicker than any other driver prior to his run, narrowly edging out McLaren's Oscar Piastri. Mercedes and McLaren traded fastest laps throughout the day, with Red Bull's Max Verstappen briefly topping the times.

Lando Norris set a benchmark of 1m34.625s early on, later improved by Verstappen to 1m33.444s and then 1m33.162s with different tyre compounds. Ferrari's Lewis Hamilton completed five laps in the morning before retiring due to an unspecified issue, finishing with a 1m33.928s lap. Aston Martin had arguably the worst day, with Fernando Alonso spending over two hours in the garage and finishing 4.669s off the pace after a troubled Wednesday that included a red flag.

Alpine's Franco Colapinto and Audi's Nico Hulkenberg provided strong midfield performances, while Williams' Alex Albon and Racing Bulls' Liam Lawson also turned in decent times. The day concluded with race start simulations, where Hamilton again showed the best launch, though Aston Martin's struggles were evident.