Isidore Clut (February 11, 1832 – July 9, 1903) was a Canadian Roman Catholic priest, Oblate of Mary Immaculate, and Auxiliary Bishop of Athabaska Mackenzie from 1864 to 1903.

He entered the Oblate novitiate at Notre-Dame-de-l'Osier in 1853 and studied theology at Montolivet in Marseilles, where he took his vows the following year.

[1] In 1857 Clut went to Canada at the invitation of Bishop Alexandre-Antonin Taché of St Boniface, who ordained him that same year.

[2] La Nativité was the episcopal see of Bishop Henri Faraud, apostolic vicar of the Vicariate of Athabasca-Mackenzie.

[3] In 1864, Faraud, for whom traveling had become difficult due to rheumatic pain, received permission to name an auxiliary bishop, and chose Clut.