Humboldt Post Office, Post office and national historic site in Humboldt, Saskatchewan, Canada

The Humboldt Post Office stands at the corner of Main Street and 6th Avenue in Humboldt, Saskatchewan. It is a 2+1⁄2-storey building with a 4-storey bell and clock tower, designed by David Ewart, chief architect of the Department of Public Works. It is the last surviving of a series of very similar prairie buildings built on a common theme.

Designed by David Ewart, chief architect of the Department of Public Works, the building opened in 1911 and was the last of a series of similar prairie post offices. It was designated a National Historic Site of Canada on 6 June 1977, a municipal heritage property in 1984 and a provincial heritage property in 2010.

The building's name comes from the German-American naturalist Alexander von Humboldt, whose name was given to the town and later to this post office. Its ground floor once combined the post office, customs and a weights and measures office, so residents came here for mail, imported goods and official measurement of goods in one visit. The clock and bell tower made it a landmark for people arriving by rail.

The building stands at the corner of Main Street and 6th Avenue, with the 4-storey bell and clock tower making it visible from several blocks away. It now houses the Humboldt & District Museum and Gallery, so the ground-floor rooms once used by the post office, customs and weights and measures office are reached on foot from the street corner.

The Humboldt Post Office is the last surviving building of a series of very similar structures built under a common theme across the Canadian prairies, all designed by David Ewart, chief architect of the Department of Public Works. Its survival makes it the only remaining example of that repeated federal design.