Leclerc punched in a 1m27.419s prior to a smattering of rainfall, which briefly intensified enough to dampen the circuit and reduce the available grip for the second half of the session.
Early on, Max Verstappen posted a 1m28.836s on the medium compound but came under threat from the Ferrari duo. Neither Leclerc nor Carlos Sainz could match Verstappen in the final sector despite running a softer grade of tyres, Leclerc setting a 1m29.000s to slot into an early second place.
The two Mercedes cars then thrust their way into the top end of the times, as George Russell split the Ferraris and Lewis Hamilton beat them to post a lap 0.13s slower than Verstappen's benchmark - albeit on the soft tyre.
Verstappen improved with a 1m28.266s, but was bettered by Sainz's next soft-tyre lap as the Spaniard placed a 1m27.964s onto the top shelf as the opening 15 minutes of the session drew to a close.
Leclerc followed up his team-mate's time, moving above Verstappen but was 0.1s off Sainz's then-benchmark lap.
Hamilton then moved to the top having posted a 1m27.948s, which Sainz could not beat on his next soft-tyre effort having haemorrhaged time in the middle sector of the lap.
With a full house of purple sectors, Leclerc then beat Hamilton with a 1m27.419s, over half a second up on Hamilton's brief benchmark.
The threat of rain then began to descend on the circuit at Turn 15, with spots of rain and lightning reported as dark clouds began to linger around the Silverstone environs, prompting a greater flurry of soft tyre runs in preparation for qualifying.
Alex Albon was resigned to remaining in the pitlane for the opening moments of the session, as an electrical issue required a burst of hotfixes from his Williams team to remedy the situation.
The Anglo-Thai driver set a best first sector on his switch to softs but fell short of Leclerc's time by 0.173s, as reports of rain began to intensify over the radio airwaves, while Aston Martin's Fernando Alonso fired his way up to third.
The rain then began to fall to coerce the drivers to retreat into their pit garages, although Leclerc elected to hang around for another lap on slicks in a presumed bid to get a feeling for the dampening circuit.
Reduced rainfall offered a handful of drivers enough courage to brave the circuit on intermediate tyres, Lando Norris the first to conduct an exploratory lap. Russell then reported that it was "spitting" but suggested that the circuit was dry enough for slicks as the drizzle subsided.
Acting as a guinea pig once again, Norris bolted on soft tyres to observe the drying conditions despite other reports of more rain being set to arrive, although a brief slip off the road at Stowe coincided with continued rain at that part of the course.
He eventually returned to the pits, leaving the track clear for just Esteban Ocon and Valtteri Bottas to cycle around on intermediate tyres as rain continued into the final 15 minutes.
Big hitters Red Bull, Ferrari, and Mercedes all used the final vestiges of the session to conduct further intermediate running, although neither Verstappen nor Leclerc was particularly impressed with the intermediate tyre life.
The majority of the field concluded the final practice session by soaking up the atmosphere with their own intermediate runs, in preparation for any further inclement weather that could affect qualifying.
Pierre Gasly slotted in behind Alonso on the timing board, ahead of Hamilton and Sainz, while Logan Sargeant also continued Williams' strong form thus far this weekend with a time good enough for seventh in the standings.
Verstappen's best lap on mediums put the current championship leader in eighth place, a smidgen clear of George Russell, while AlphaTauri pair Yuki Tsunoda and Nyck de Vries were 10th and 11th - beating the 12th-placed Norris.
Norris had an incident investigated by the stewards as his McLaren team left a cooling fan at the back of his car and was asked to stop at the pitlane exit to allow a mechanic to retrieve the errant air displacement device. This incident would be investigated after the session.
Following a post-session investigation, McLaren was handed a €1000 fine and an official warning from the FIA.
| Cla | Driver | Chassis | Engine | Laps | Time | Gap | |
|---|---|---|---|---|---|---|---|
| 1 |  Charles Leclerc |
 |
Ferrari | Ferrari | 24 | 1'27.419 | |
| 2 |  Alex Albon |
 |
Williams | Mercedes | 14 | 1'27.592 | 0.173 |
| 3 |  Fernando Alonso |
 |
Aston Martin | Mercedes | 17 | 1'27.784 | 0.365 |
| 4 |  Pierre Gasly |
 |
Alpine | Renault | 19 | 1'27.893 | 0.474 |
| 5 |  Lewis Hamilton |
 |
Mercedes | Mercedes | 16 | 1'27.948 | 0.529 |
| 6 | Carlos Sainz |
 |
Ferrari | Ferrari | 21 | 1'27.964 | 0.545 |
| 7 |  Logan Sargeant |
 |
Williams | Mercedes | 16 | 1'28.151 | 0.732 |
| 8 |  Max Verstappen |
 |
Red Bull | Red Bull | 19 | 1'28.266 | 0.847 |
| 9 | George Russell |
 |
Mercedes | Mercedes | 17 | 1'28.284 | 0.865 |
| 10 |  Yuki Tsunoda |
 |
AlphaTauri | Red Bull | 21 | 1'28.337 | 0.918 |
| 11 | Nyck de Vries |
 |
AlphaTauri | Red Bull | 20 | 1'28.504 | 1.085 |
| 12 | Lando Norris |
 |
McLaren | Mercedes | 18 | 1'28.563 | 1.144 |
| 13 |  Lance Stroll |
 |
Aston Martin | Mercedes | 15 | 1'28.620 | 1.201 |
| 14 |  Sergio Perez |
 |
Red Bull | Red Bull | 19 | 1'28.904 | 1.485 |
| 15 |  Kevin Magnussen |
 |
Haas | Ferrari | 13 | 1'29.207 | 1.788 |
| 16 | Esteban Ocon |
 |
Alpine | Renault | 22 | 1'29.233 | 1.814 |
| 17 |  Oscar Piastri |
 |
McLaren | Mercedes | 20 | 1'29.437 | 2.018 |
| 18 |  Valtteri Bottas |
 |
Alfa Romeo | Ferrari | 15 | 1'29.586 | 2.167 |
| 19 |  Nico Hulkenberg |
 |
Haas | Ferrari | 13 | 1'33.590 | 6.171 |
| 20 |  Zhou Guanyu |
|
Alfa Romeo | Ferrari | 2 | ||
| View full results | |||||||
