René Gagnier (30 May 1892 – 25 May 1951) was a Canadian conductor, composer, euphonium player, violinist, and music educator.
His compositional output includes several marches, waltzes, works for solo violin, and some chamber and symphonic music, all of which remains unpublished.
His later teachers included violinists Saul Brant, Albert Chamberland, and Alfred De Sève.
[1] From 1918 to 1929, Gagnier served as the assistant conductor of Loew's Theatre in Montreal.
As a euphonium player he performed for over 25 years with the Canadian Grenadier Guards Band, which was directed by his older brother J.-J.