John "Jack" Roos was a Canadian ice hockey player and coach who led the program at Clarkson to three eastern intercollegiate titles in the 1930s.

In 1929, after the death of star player Harry Heintzman and the resignation of Gordon Croskery, Roos was brought in to be the head coach at Clarkson.

On top of that, Clarkson was named by the associated press as the national ice hockey champion, though that title isn't official.

Roos had another near miss championship in 1941 and then watched as World War II sapped both his team and all of college hockey of their players.

After a solid, if unspectacular, season in 1948, Roos retired from his position and turned the program over to Bill Harrison.