The Mercedes AMG teammates, who have won all six races to start the Formula One season, had dinner and a long chat and decided to stop exchanging barbs as they battle each other for the championship.
Hamilton wrote in a recent tweet that "we're cool, still friends." He made it official at the pre-race drivers' news conference on Thursday.
"Now, full steam ahead," Hamilton said at the Canadian Grand Prix. "We had dinner with the team (Wednesday) and things have never been better.
"People have ups and downs, so it's no different from any other experience me and Nico have had in our whole, who knows how many years we've been racing together. We move on. We're pushing forward. There's a long way to go in the season, so I'm looking forward to that battle."
It was Hamilton who reportedly called Rosberg last week to begin the peace process.
Their sniping came to head two weeks ago at the Monaco Grand Prix, where Hamilton felt he was cheated out of a chance to win pole position when Rosberg pulled off the track late in qualifying, bringing out a caution flag. Hamilton refused to join Rosberg on the post-race podium to celebrate the German-Finnish driver's victory.
Earlier, Hamilton caused a stir by suggesting he was hungrier for victory than Rosberg, the son of former F1 star Keke Rosberg, because of his humble background.
Hamilton, 29, and Rosberg, 28, developed together as drivers in the Mercedes system.
Rosberg's win in Monaco put him four points ahead of Hamilton in what has become a two-car championship.
Mostly, it has been Hamilton making comments and Rosberg taking the high road by not responding. But Rosberg said tensions are normal between close competitors.
"I try to err towards the rational side. It's hard sometimes in this sport," said Rosberg.
"Of course it's more difficult when we're fighting every single race weekend. It's against him and there's nobody else and that makes it more difficult. There's more at stake. There is the opportunity of winning the championship this year and that's the ultimate goal in racing."
Team management may have had a hand in the reconciliation. The drivers were given the go-ahead to battle for wins, so long as they didn't bash into each other on the track. But the bitterness seemed to be escalating.
Rosberg admits it is more difficult to race against a teammate because if they bump, it could take points away not only from the drivers but from the team.
"If we take each other out, for all our team members it would be a disaster," he said.
That may be the only hope rival teams have of catching Mercedes AMG, who nailed the 1.5-litre engines introduced this year to produce easily the quickest cars on the grid.
Sebastian Vettel, whose run of four straight F1 titles is all-but certain to end, isn't counting on a Mercedes implosion.
"If they hit each other, then it's good for us to take points off them," said Vettel. "But I think they're clever enough not to, so you can't rely on that."
Rosberg ended Hamilton's four-racing winning run in Monaco, but the Briton will be the favourite in Montreal, where he has won three times.
But just because they're friends again, doesn't mean Rosberg isn't ready to battle on the track.
"I'm here to win," he said. "I'm approaching the weekend with that state of mind, and I know that in every race, if I manage to nail it, everything's possible."