Fortuna is in western Moniteau County and is bordered to the southwest by
Morgan County.
Missouri Route 5 passes through the community, leading north to
Tipton and south to
Versailles.
California, the Moniteau
county seat, is to the northeast. According to the
U.S. Census Bureau, the Fortuna CDP has an area of , all land. The town sits on a ridge which drains southeast to the Straight Fork of North Moreau Creek and northwest to Little Richland Creek. North Moreau Creek is an east-flowing tributary of the
Moreau River, which joins the
Missouri River near
Jefferson City, while Little Richland Creek is a northwest-flowing tributary of the
Lamine River, which runs north to the Missouri west of
Boonville. ==Demographics==