The Warriors secured a 129-120 victory on Monday to take their second title in three seasons and cap a near-perfect run through the play-offs.
Golden State beat Cleveland in the 2015 Finals only to lose to them last year, squandering a 3-1 series lead.
Warriors forward Kevin Durant, 28, was named the Most Valuable Player of the Finals.
"I couldn't sleep for two days," Durant said. "I was anxious, I was jittery.
"I just wanted to lay it all out there. I put in work, I just had to trust in it. We were really good tonight."
For the third year in succession the two teams met in the Finals, but after going 3-0 down this time around, Cleveland were only able to pull one game back before the Warriors secured the trophy in game five.
Durant, who joined from the Oklahoma City Thunder last summer, was key to the Warriors' victory and their 16-1 postseason run - the best in the league's history.
The first-time title winner scored 39 points as point guard Stephen Curry posted 34 at the Oracle Arena in Oakland.
LeBron James, last year's Finals MVP, led the Cavaliers with 41 points, 13 rebounds and eight assists but it was not enough as the home team came out on top.
Durant - drafted as second-overall pick by the Seattle SuperSonics in 2007 - was an easy choice for the Finals MVP.
After joining the Warriors in July 2016 - a decision which caused shockwaves in the NBA world among talk of a GSW 'super team' - it took Durant just one season to win his first championship.
The two-time US Olympic gold medallist scored more than 30 points in each of the five games - the first player since Shaquille O'Neal in 2000 for the LA Lakers - and averaged 35.2 per game across the series.
He also added 8.2 rebounds and 5.2 assists a game.
But Durant was quick to congratulate last year's champions. "You have to tip your hat to Cleveland," he added.
"LeBron and Kyrie I've never seen nothing like them two before. But we prevailed, we're champions and it's amazing doing it on our home floor."
On his match-up with Cavaliers' forward LeBron James, Durant added: "He's the only person that I was looking at since 2012,"
"I knew it was going to be a battle I just tried to challenge him - you can't stop the guy.
"I told him we're tied up now and we're going to try to do this thing again but I'm going to celebrate this one tonight."
Golden State Warriors in numbers
What's next for LeBron James?
LeBron James has now lost five Finals in eight appearances - only the fourth player to come up short in five NBA Finals.
But three-time champion LeBron said he had no reason to feel sorry for himself.
"I left everything on the floor every game, all five games," he said. "I have no reason to put my head down."
"I played against some really, really good teams that were assembled perfectly, and they're right up there."
The four-time league MVP is now in the latter stages of his career after 14 NBA seasons - and questions are mounting over his future.
The now 32-year-old was selected by his home team, the Cleveland Cavaliers, as the first overall pick of the 2003 NBA draft.
He was vilified in 2010 when he left the Cavs to join the Miami Heat - where he won two NBA titles - before returning to Cleveland four years later to help win a first championship for the city in 2016.
He will be an unrestricted free agent in 2018 and has not spoken about whether he will stay with the franchise beyond that time.