The reigning world champion beat team-mate Valtteri Bottas by more than 16 seconds as Mercedes clinched their sixth one-two finish of the 2019 season.
Ferrari's Charles Leclerc finished a close third, and Red Bull's Max Verstappen took fourth as the front four starters on the grid kept their places at the chequered flag.
Sebastian Vettel started seventh and made up ground to clinch fifth, but he couldn't prevent Mercedes' leading pair from breaking further ahead of the chasing pack.
The official Formula One Twitter account posted Sunday's classification in full:
A relentless display from Hamilton saw the Briton lead from start to finish and break the lap record on multiple occasions, settling on a new fastest time of one minute, 32.764 seconds with his final attempt.
After failing to win a French Grand Prix until 2018, Hamilton has now secured back-to-back crowns and is en route to winning three successive world titles for the first time in his career.
The 34-year-old was elated after his win but showed gratitude to the Mercedes team:
Commentators debated over the quality of the race considering there was so little change of order among the leaders.
BBC 5 Live Sport described the outing as a "straightforward Sunday afternoon" for Hamilton:
BBC 5 Live Sport @5liveSport
"This has been a straightforward drive in the south of France" 🏆 Lewis Hamilton extends his championship lead to 36 points. 👂Listen back to the closing stages of the #FrenchGP 🏴 Now it's over to the #Lionesses 📻 Reaction 👉 https://t.co/mulR2LcyFP #BBCF1 https://t.co/wiSRTs5uUa
Carlos Sainz and Verstappen engaged in one of the more entertaining head-to-head battles early on, with the Dutchman under pressure to keep his place in fourth.
Lando Norris started fifth on the grid and earned plaudits for his display despite finishing 10th. McLaren's Sainz kept sixth and Renault's Daniel Ricciardo pushed one place up the leaderboard to finish seventh.
The scorching temperatures at Circuit Paul Ricard in Le Castellet were having a heavy impact on wear and tear. It was around Lap 25 that drivers started pitting, with most swapping medium tyres for a hard set:
Hamilton held an advantage of more than 12 seconds after 39 laps and only increased that gap as the race wore into its latter stages, with most of the excitement coming from further back in the field.
Leclerc made a late push to snatch second from Bottas and almost cut in front of the Finn to break Mercedes' hold, falling short by a little less than one second.
There's still more than half of the 2019 campaign left to race, but Hamilton has already carved out a lead that will be hard to cut down, not to mention the gap between Mercedes and the rest of the pack.
ESPN F1 highlighted more statistics in favour of both driver and manufacturer:
The win also secured a fourth successive Formula One victory for the in-form leader, who is still yet to finish outside the top two in any race this season.
Drivers will only have a few days respite before preparations begin for the 2019 Austrian Grand Prix in Spielberg next Sunday, where Verstappen is the titleholder.