Ellis was selected by the Los Angeles Lakers in the first round (8th pick overall) of the 1962 NBA draft.

He played in 1,048 games over 14 seasons (1962–1976) in the NBA with the Lakers, Baltimore Bullets, Portland Trail Blazers, and Philadelphia 76ers, and was a member of the 1971–72 Los Angeles Lakers championship team,[2] which also won a then-record 69 games in the regular season, and recorded the longest winning streak in NBA history with 33 wins.

Ellis was on the first Portland Trail Blazers team in 1970–71, selected from Baltimore in the 1970 expansion draft.

[5] He continued playing basketball long after his professional career ended, including being a part of several Senior Masters Games national championship teams in Portland.

[2] LeRoy Ellis was accompanied by his son, LeRon, and the two moved to the city of Anaheim, California while waiting for the rest of their family to join them at a later time.