The experienced England international arrives in north London on a free transfer following his release from Burnley at the end of last season.
The 33-year-old becomes Tottenham's second signing of the summer after Pierre-Emile Hojbjerg, who joined the club for £15 million from Southampton.
Hart is expected to compete with Paulo Gazzaniga as understudy to Mourinho’s No1 goalkeeper and captain Hugo Lloris following the departure of Michel Vorm.
During 12 years at Manchester City, Hart won two Premier League titles, two League Cups and an FA Cup.
Hart fell out of favour at the Etihad Stadium after Pep Guardiola's arrival in 2016 and had loan spells at Torino and West Ham.
He joined Burnley in 2018 and made 24 appearances but was behind Nick Pope last term.
Hart, who started his career at Shrewsbury, has 75 caps for England but has not played for his country for almost three years.
Additional reporting from Press Association
Read More
MORE ABOUT