And they can thank fierce rival Manchester United for that.
City are 16 points clear of second-placed United, who can only take a maximum of 15 points from their remaining five games. Our Time. Our City.
United produced a subdued performance against the Baggies and were beaten by a 73rd-minute header from Jay Rodriguez.
After starting the title party with his Mancunian wife and his United-supporting father-in-law, City captain Vincent Kompany joined team-mates to raise a glass to their success.
'I was not going to celebrate like insane, for me we should play with great focus and intensity and try and kill the top four situation and be more stable in second.
Mourinho acknowledged that "Metropolis have been the very best group" within the Premier League, telling the BBC: "Ultimately they'd get the factors, so no dramas when the very best group wins the league".
Manchester United boss Jose Mourinho has urged his players to be more consistent next season if they are to challenge Manchester City for the title next season.
'We were masters in complication.
"The best way to achieving that is to aim for stability at training level, during the working week, and from what I have seen in the past two or three weeks I am really happy with him".
An 18-match winning run from late August to late December laid City's platform for the runaway title victory, and it was only a matter of when it would be clinched.
Few - including Guardiola - expected it to happen on Sunday.
"I know that sooner or later that would be and if I was in that position I would be very upset if somebody say they won the title because Manchester United lost to West Bromwich Albion", said Mourinho.
Pogba was substituted after 57 minutes of United's defeat, and Mourinho did not make any attempt to hide his unhappiness with the team's performance and the inconsistency of his most expensive player. "We didn't need to lose, we gave them alternative to win the match".
City have unquestionably been the best team in England but their status has been undermined by their Champions League exit.