They are only the second English men’s side to win the Premier League, FA Cup and Champions League in the same season after Manchester United in 1999.
Supporters gathered at Manchester Airport as City landed at 16:20 BST.
Thousands more are expected to line the streets in Manchester city centre for a victory parade on Monday.
The City squad will travel in an open-top bus through the city, before a stage show takes place with Guardiola and his players.
Fans gathered to welcome the triumphant City squad homeJack Grealish and John Stones were the two English starters for City in the finalManchester City landed at about 16:20 BST on SundayKevin de Bruyne snapped a hamstring during the first half of City’s win, but was able to enjoy the celebrations on the flight homeThe City squad will travel in an open-top bus through Manchester city centre on MondayPhil Foden came on as a first-half substitute for the injured De Bruyne