The six-foot-nine forward — who played for the Indiana Pacers last season — tweeted the news from his verified Twitter account early Thursday.
"We the north ... Here I come," said Scola, who added a smiley face in his tweet.
The announcement came just after the league's moratorium was lifted at midnight on deals and trades that were agreed to since free agency opened on July 1.
In 81 games last season for the Pacers, the 35-year-old Scola averaged 20.5 minutes, 9.4 points and 6.5 rebounds.
Canadian Cory Joseph of Pickering, Ont., announced on Sunday that he would also be joining Toronto.
The Raptors have called news conferences for 10 a.m. and 11:30 a.m. on Thursday where president and general manager Masai Ujiri will make what the team calls major announcements.