Leclerc set his quickest time of 1:30.322 on the C4 soft compound tyres with George Russell only +0.046 behind the Monegasque in second.
For the second consecutive day, testing was stopped for over an hour after a drain cover came loose during on-track running with Sergio Perez - the one who caused the cover to come loose.
Despite frantic work from the Red Bull mechanics and the team’s chief technology officer, Adrian Newey, to check for damage, Perez’s car seemingly emerged unscathed.
Perez handed the driving duties to teammate Max Verstappen for the second half of the day with the Dutchman setting the fourth fastest time of the day on the C3 medium tyres.
Yuki Tsunoda and Alex Albon rounded off the top six, with Oscar Piastri and Fernando Alonso separated by over a tenth in seventh and eighth.
F1 Testing Results: Day Three
Below is the full classification from the third day of testing in Bahrain:
1. Charles Leclerc (Ferrari) - 1:30.322, 74 laps
2. George Russell (Mercedes) - +0.046, 67 laps
3. Zhou Guanyu (Kick Sauber) - +0.325, 85 laps
4. Max Verstappen (Red Bull) - +0.433, 66 laps
5. Yuki Tsunoda (RB) - +0.453, 53 laps
6. Alex Albon (Williams) - +0.662, 121 laps
7. Oscar Piastri (McLaren) - +0.708, 91 laps
8. Fernando Alonso (Aston Martin) - +0.837, 75 laps
9. Carlos Sainz (Ferrari) - +0.925, 71 laps
10. Sergio Perez (Red Bull) - +1.161, 53 laps
11. Nico Hulkenberg (Haas) - +1.364, 89 laps
12. Lewis Hamilton (Mercedes) - +1.677 49 laps
13. Lance Stroll (Aston Martin) - +1.716, 46 laps
14. Lando Norris (McLaren) - +1.786, 20 laps
15. Pierre Gasly (Alpine) - +1.827, 47 laps
16. Kevin Magnussen (Haas) - +2.731, 80 laps
17. Esteban Ocon (Alpine) - +2.757, 55 laps
18. Valtteri Bottas (Kick Sauber) - +3.206, 28 laps
19. Daniel Ricciardo (RB) - +6.693, 70 laps