1983–84 Long Island Blackbirds men's basketball team

The 1983–84 Long Island Blackbirds men's basketball team represented Long Island University during the 1983–84 NCAA Division I men's basketball season. The Blackbirds, led by head coach Paul Lizzo, played their home games at the Schwartz Athletic Center and were members of the ECAC Metro Conference. They finished the season 20–11, 11–5 in ECAC-M play to capture the regular season championship. They also won the ECAC Metro tournament to earn an automatic bid in the 1984 NCAA tournament where they lost in the play-in round to Northeastern, 90–87.

Schedule and results
!colspan=9 style=| Regular season

!colspan=9 style=| ECAC Metro tournament

!colspan=9 style=| NCAA tournament