Esteban Ocon was first on track and first to set a lap, posting a 1m31.125s on the medium compound which proved to be enough for an early edge over Lewis Hamilton on softs.
The Ferrari duo then set their first laps of the session on softs and, of the two, Carlos Sainz posted the faster time with a 1m30.748s, three tenths clear of Charles Leclerc's first lap as the Monegasque recovered from his FP2 crash on Friday.
Ocon then vaulted above them with a second tour on mediums, but was beaten by Alpine team-mate Pierre Gasly on the same compound.
Then came the Red Bulls to set their first attempts at headline times on soft boots; Sergio Perez put in a 1m29.266s, but this was quickly beaten by Max Verstappen's 1m28.963s - approximately a second off the ultimate pace in FP2.
Leclerc split the Red Bulls with a 1m29.057s, also on softs, to get within a tenth of Verstappen's early benchmark, which stood for about five minutes until Perez punched in a 1m28.641s.
Fernando Alonso moved into third on mediums, just over three tenths shy of Perez, but Verstappen then replicated his pace from FP2 with a 1m27.969s to blow Perez's time into the reeds.
Sainz's next hot lap closed the gap to Verstappen, with the Spaniard's 1m28.125s getting to within two tenths of the pace, as drivers reported rapidly improving track conditions as grip proved to be at a premium over the opening day.
Verstappen subsequently added to his advantage with a 1m27.669s, which remained untroubled throughout much of the middle portion of the session as teams sought to catch up with the long-run simulations they'd missed out on during FP2 following Leclerc's late crash.
The Dutchman then extended his advantage with 15 minutes to spare, chipping just under a tenth off of his benchmark as he elected to resume his purple sector-chasing exploits in the final quarter of the session.
His progression continued, and he knocked another 0.06s out of his best time as the session wound down into its final 10 minutes, with an advantage of well over 0.6s over the rest of the field.
Perez closed that down with a 1m28.050s, before he was pipped at the death by Leclerc - who hammered in a 1m27.941s to move up to second.
Sainz's time, which remained second best for much of the session, kept him in fourth overall with a near 0.3s gap to the upper midfield runners. The Ferrari driver logged the most laps of FP3's run-time, with 27 tours of the Miami circuit.
Ocon beat Gasly to fifth spot by 0.02s, as Valtteri Bottas made his way up to seventh fastest in the session ahead of Nico Hulkenberg.
Alex Albon was ninth fastest ahead of FP1 headliner George Russell, who complained that the Mercedes' balance was "okay, but just struggling for overall pace" and reported "hopping" at Turn 2 - something he experienced in FP2 on Friday.
Kevin Magnussen moved ahead of Alonso to sit 11th to complete a strong session for the Haas team on home soil, as Hamilton was 13th fastest as Mercedes struggled for competitiveness.
| Cla | Driver | Chassis | Engine | Laps | Time | Gap | |
|---|---|---|---|---|---|---|---|
| 1 |
 Max Verstappen |
 |
Red Bull | Red Bull | 18 | 1'27.535 | |
| 2 |
 Charles Leclerc |
 |
Ferrari | Ferrari | 26 | 1'27.941 | 0.406 |
| 3 |
 Sergio Perez |
 |
Red Bull | Red Bull | 22 | 1'28.050 | 0.515 |
| 4 |
 Carlos Sainz |
 |
Ferrari | Ferrari | 27 | 1'28.125 | 0.590 |
| 5 |
 Esteban Ocon |
 |
Alpine | Renault | 25 | 1'28.407 | 0.872 |
| 6 |
Pierre Gasly |
 |
Alpine | Renault | 24 | 1'28.428 | 0.893 |
| 7 |
 Valtteri Bottas |
 |
Alfa Romeo | Ferrari | 19 | 1'28.456 | 0.921 |
| 8 |
 Nico Hulkenberg |
 |
Haas | Ferrari | 16 | 1'28.497 | 0.962 |
| 9 |
 Alex Albon |
 |
Williams | Mercedes | 20 | 1'28.561 | 1.026 |
| 10 |
 George Russell |
 |
Mercedes | Mercedes | 20 | 1'28.606 | 1.071 |
| 11 |
 Kevin Magnussen |
 |
Haas | Ferrari | 14 | 1'28.607 | 1.072 |
| 12 |
Fernando Alonso |
 |
Aston Martin | Mercedes | 24 | 1'28.618 | 1.083 |
| 13 |
Lewis Hamilton |
 |
Mercedes | Mercedes | 23 | 1'28.718 | 1.183 |
| 14 |
 Lance Stroll |
 |
Aston Martin | Mercedes | 24 | 1'28.723 | 1.188 |
| 15 |
 Zhou Guanyu |
 |
Alfa Romeo | Ferrari | 19 | 1'29.074 | 1.539 |
| 16 |
 Yuki Tsunoda |
 |
AlphaTauri | Red Bull | 20 | 1'29.179 | 1.644 |
| 17 |
 Logan Sargeant |
 |
Williams | Mercedes | 20 | 1'29.264 | 1.729 |
| 18 |
 Oscar Piastri |
 |
McLaren | Mercedes | 18 | 1'29.375 | 1.840 |
| 19 |
Lando Norris |
 |
McLaren | Mercedes | 18 | 1'29.401 | 1.866 |
| 20 |
Nyck de Vries |
 |
AlphaTauri | Red Bull | 22 | 1'29.447 | 1.912 |
| View full results | |||||||
