The Halifax Canadiens were a junior team.
The first team with that name played in the Halifax City Junior League. They won this league championship in 1934, 1935, 1936, 1937, 1938, 1942, and 1943. They entered the Maritimes Junior Championships in each of these years plus in 1941. The league did not operate in 1941 and the Canadiens entered as an independent (non-league) team.
The Canadiens won the Maritimes championship in 1938 and 1942. They lost the quarter finals in the Eastern Canada playoffs in both seasons.
The second team was set up as a farm team by the Montreal Canadiens in 1965. It played as an independent team for three seasons (1965-66, 1966-67, and 1967-68), The Canadiens played against local senior, junior, and university teams plus games against junior teams from Ontario and Quebec. There was even some talk of the team joining the Ontario Hockey Association's junior league, which was the premier junior league of its time.
The Canadiens won the Maritimes Junior Championship in each of these three seasons but did not get too far in the Easrern Canada Memorial Cup Playoffs.
In 1968-69 the Canadiens joined a three team Maritime Junior Hockey League. They won the title but again they had no success in the Eastern Canada playoffs.