Arsenal, who had a dominant campaign and led the league for almost the entire season, were confirmed as champions without kicking a ball after second-placed Manchester City drew 1-1 at Bournemouth.
The players had gathered at the club's training ground an hour north of London to watch the match and video released on social media showed them leaping around and hugging one another once the club's 14th English title was assured.
In London, fans streamed out of pubs and houses and gathered outside the club's Emirates Stadium, setting off fireworks and flares while chanting "Champions! Champions! Ole! Ole! Ole!".
"Words can't describe it, we've been waiting 22 years for this. It's unbelievable," an Arsenal fan told Reuters TV.
"Bournemouth did us a massive favour today, they played so well. And we're deserved champions, so happy days."
Arsenal great Ian Wright also joined the party outside the stadium and was mobbed by fans singing his name.
"I was absolutely over the moon," Wright, who scored 185 goals for the club in the 1990s, told Premier League Productions.
"I got in the cab, got my Mrs and my girls in the cab and I said, 'We're going down there, let's go down to the Emirates.'"
"It's amazing, honestly, and this club deserves it. Our fans deserve it all, around the world and everybody, we deserve this, man."
Arsenal finish their Premier League campaign with a trip to Crystal Palace on Sunday, before they move on to face Paris St Germain in the Champions League final in Budapest on May 30.