Toronto announced the deal with the restricted free agent on Saturday. The terms were not disclosed.
The 6-foot-9 Patterson was acquired in a seven-player trade with Sacramento in December. He averaged 9.1 points and 5.1 rebounds in 48 games with the Raptors.
Masai Ujiri, Toronto's team president and general manager, says ''We were very pleased with what Patrick brought to us both on the court and in the locker room last season.''
The 25-year-old Patterson is averaging 8.4 points and 4.6 rebounds over 252 career NBA games with Houston, Sacramento and Toronto. He was selected by the Rockets with the 14th overall pick in the 2010 draft.