The Mercedes driver edged out teammate Nico Rosberg by a huge 0.698 seconds to prove he is back on top after Formula One's summer break.
His German title rival had gone into qualifying haunted by a high-speed tire blowout during Friday practice.
There were serene conditions on Saturday for Hamilton, who clocked a best lap of one minute and 47.197 seconds at the rollercoaster Spa-Francorchamps circuit, the longest track of the season at seven kilometers.
"My last two laps were my best two laps of the weekend," Hamilton, who grabbed his sixth pole in a row, told the media. "I'm really happy with the performance of the car."
Valtteri Bottas finished in third place for Willams and will line up on the second row alongside the Force India of Sergio Perez. Romain Grosjean had qualified third for Lotus but took a five-place grid penalty for changing a gearbox before qualifying.
Rosberg's preparations were undeniably upset when one of his rear tires blew out during a practice session on Friday afternoon.
He had set the fastest time of the day but told the media his confidence had been damaged by the high-speed incident.
"It was quite a shocking moment for me when my rear tire failed," Rosberg revealed. "When you are going as fast as 300 kph (186 mph) and something goes wrong, that's a horrible feeling.
"I thought I would end up in the wall and, to be honest, it was pure luck that I didn't."
Mercedes technical director Paddy Lowe had described the incident as a "very unusual situation."
He added: "There seemed to be some bits of tire structure coming out up to a minute before the actual terminal failure of the tire."
Italian manufacturer Pirelli issued a statement on Saturday confirming it had investigated the incident and excluded any "structural integrity issues," instead pointing to an "external source of damage."
But, after qualifying, Rosberg said the situation remained unclear: "The problem is that we don't really understand it.
"There are theories but no real evidence. That's a bit worry for sure. We've taken some measures to make sure it doesn't happen again."
It emerged that leading racers including Hamilton, Ferrari's Sebastian Vettel and McLaren's Fernando Alonso had expressed concern about tire reliability in Friday's drivers' meeting.
Hamilton may have recalled losing the lead of the British Grand Prix in 2013 when his tire unraveled. His was the first of four tire blowouts during that race
, which forced Pirelli into major tire changes.
Race director Charlie Whiting also explained, in another media statement, that a bump at the exit of the first corner, known as La Source, had been shortened by 10 meters ahead of qualifying. A curb at the exit of the famous uphill sweep at Eau Rouge had also been removed to help prevent further incidents.
There were no tire issues during qualifying, when the rubber is pushed to its limit over a single lap.
But Hamilton remained cautious about the prospect of tires issues looming during Sunday's race around Spa's punishing high-speed corners.
"Tires are an unknown from the degradation point of view but seeing Nico's issues yesterday, who knows what's going to happen in the race," said the British driver, who has won 10 out of 11 poles this season.
Rosberg's hopes of reigniting his title challenge may have deflated in the wake of Hamilton's stunning performance. The 30-year-old is 21 points behind the two-time world champion with nine races remaining.
"For sure I'm disappointed," said Rosberg, whose wife Vivian is expecting their first child in a matter of days.
"Lewis was too quick in the end. He found quite a lot extra which I didn't have in my pocket."
There was also dejection for Kimi Raikkonen, who had arrived in Spa in unusually high spirits after his contract with Ferrari was renewed for 2016.
Qualifying was interrupted when the Finn's car suddenly lost power and he had to be pushed clear of the circuit.
"Something broke," bemoaned the fans' favorite on the pit-to-car radio. Raikkonen will start from 14th while his teammate Vettel -- the only driver other than the Mercedes duo to win a race in 2015 -- will line up in eighth.