The teams announced the deal Thursday.
Sacramento selected McCallum in the second round and 36th overall in 2013. McCallum averaged 6.9 points, 2.7 assists and 20.7 minutes per game the past two seasons.
It was clear McCallum's time in California's capital city could be ending after the Kings reached an agreement on a one-year, $10 million deal with Rajon Rondo last week. Rondo and Collison are expected to split time in the backcourt.