Blaise-Ferdinand Letellier, KC (June 22, 1862 – December 15, 1930) was a Canadian lawyer, politician, and judge.
Born in Lévis, Canada East, the son of Blaise Letellier and Émérentienne Lacombe.
Letellier was educated at the Séminaire de Québec and Université Laval.
He was called to the Quebec Bar in 1886 and was created a King's Counsel in 1903.
He was a defeated candidate for the Legislative Assembly of Quebec in the riding of Dorchester in 1900 and in Beauce in a 1902 by-election.