The 18-year-old spent time with the Bairns as a youth before switching to the Capital club and has now returned to the Falkirk Stadium after signing on until the end of the season.
He will compete with Robbie Mutch and Motherwell loanee PJ Morrison as the club's options between the sticks.
Cantley, a former Broughton High School pupil, has already been involved with the League One club this season as a trialist, although only as an unused substitute.
During his time at Easter Road Cantley occasionally featured for the club’s development squad but was very much behind Kevin Dabrowski and Paddy Martin in the pecking order.
Ironically, the shot-stopper could come up against former colleague Dabrowski when the Bairns travel to face Dumbarton on Tuesday November 24.
The Polish No.1 signed a season-long loan deal with the Sons in the summer and is first-choice at the C&G Systems Stadium.