Leif Newry Fitzroy Crozier (11 June 1846 – 25 February 1901), commonly known as L. N. F. Crozier, was a Canadian Militia officer and a superintendent of the North-West Mounted Police (NWMP), now best remembered for his role in the North-West Rebellion of 1885, a resistance movement headed by Métis leader Louis Riel in what is now the modern province of Saskatchewan.

He warned Lieutenant-Governor Edgar Dewdney that government policies were creating unrest among the First Nations and Métis.

[citation needed] Wanting to avoid conflict, he attempted to negotiate with Louis Riel but was unsuccessful leaving the situation in a stalemate.

These men were confronted by Gabriel Dumont and a superior force of Métis near Duck Lake, Saskatchewan; no shots were fired and the police returned to Fort Carlton.

[citation needed] Crozier's role in the remainder of the rebellion was minimal, and his force largely remained at its post in Battleford, Saskatchewan.