Ernest John Dubeau (April 19, 1882 – June 19, 1951) was a Canadian professional ice hockey defenceman.

He returned east in 1908 and played for the Berlin Dutchmen of the Ontario Professional Hockey League, and the Montreal Shamrocks of the ECHA.

He played four games for Montreal Le National of the Canadian Hockey Association before the league folded.

He played for Trenton in his home province of Ontario in 1910–11, before winning a starting job with the Montreal Canadiens for the 1911–12 season.

He played four seasons with the team before he was traded to Toronto for Skene Ronan on January 17, 1916.