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.
