Fort Sandoské was a French military fort, built about 1750 on what is now called the Marblehead Peninsula on the northern side of Sandusky Bay in Ohio, near the traditional portage place from the bay to Lake Erie.
It was built at a site formerly occupied about 1745 by a trading-post run by mostly Pennsylvanian ("English") fur-traders, who had been given permission by Wyandot chief Nicolas Orontony.
The English Fort Sandusky was not built until 1761 and it was constructed in a different location southeast of the bay.
It was already abandoned by 1754, when French lieutenant and engineer Gaspard-Joseph Chaussegros de Léry passed through the area with forces to reinforce Fort Detroit.
He sketched the remains of this fort's layout/plan and included it in a campaign journal, one of eight of his held by Laval University in Quebec.