Ellington averaging 10.0 points in 65 games for the Lakers last season, including a career-best 36 starts. He has averaged 7.0 points in 377 games with five teams.
Terms of the deal announced Friday were not disclosed.
Nets general manager Billy King says Ellington ''is a proven shooter who will give us added depth on the wing.''
Ellington was taken by Minnesota with the 28th pick in the 2009 draft, after he was Most Outstanding Player of the Final Four in leading North Carolina to the national championship. The 27-year-old Ellington has also played for Memphis, Cleveland and Dallas.