Fort de Buade was a French fort operating at the present site of St. Ignace, Michigan, from 1683 to 1701. It was built to establish a strategic presence on the north shore of the Straits of Mackinac, where Lake Michigan and Lake Huron come together. The French-Canadian settlement at St. Ignace prior to 1683 was an unfortified fur-trading station and mission, founded by Father Jacques Marquette, S.J. in 1671.

In the 1690s, reports of English-speaking fur traders on the Great Lakes multiplied. These reports, in 1701, inspired Fort de Buade's commander, Antoine de la Mothe Cadillac, to move the garrison south to a different strategic location on the Detroit River. The Fort de Buade garrison thus indirectly helped give birth to the future city of Detroit.

The 1683-1701 Fort de Buade was probably a wooden stockade. It is believed to have been located near Moran Bay on the waterfront of the current village of St. Ignace, but as of January 2006 its remains had not yet been identified.

In 1715 a French detachment re-established a presence at the Straits of Mackinac. The new fort, called Fort Michilimackinac, was raised on the south shore of the Straits near the present location of Mackinaw City, Michigan.

Forts in Michigan