William Alvin Nicolai (born May 15, 1890) was the seventh head college football coach for the Temple University Owls located in Philadelphia, Pennsylvania, USA, a position he held for three seasons, from 1914 until 1916. His overall coaching record at Temple was 9 wins, 5 losses and 3 ties. As of completion of the 2007 season, this ranks him 13th at Temple in terms of total wins and third in terms of winning percentage.  In his final season at Temple, his team played six games and conceded only 14 points in the entire season.
Nicolai also served as a professor at Temple University.