The England international defender has penned a five-year deal at Goodison Park.
Everton have paid an initial £25m to the Clarets, with a potential £5m more to come, which would match the Toffees' record outlay, the fee they spent to bring Romelu Lukaku to the club from Chelsea.
Having become Burnley's most expensive player in history, Keane said the chance to work with former Netherlands and Barcelona defender Ronald Koeman was too good to turn down.
