The 2004–05 Niagara Purple Eagles men's basketball team represented Niagara University during the 2004–05 NCAA Division I men's basketball season.

The Purple Eagles, led by seventh-year head coach Joe Mihalich, played their home games at the Gallagher Center in Lewiston, New York as members of the Metro Atlantic Athletic Conference.

They defeated Iona and Rider to win the MAAC tournament and secure the conference's automatic bid to the NCAA Tournament as the No.

14 seed in the South region.

3 seed Oklahoma, 84–67, in the opening round.