Rosati, Missouri is a small, unincorporated community on Missouri Supplemental Route ZZ in eastern Phelps County four miles (6 km) east of St. James. This road is also former U.S. Highway 66. The community was originally settled after 1845 and was known as Knobview, due to its view of three knobs or hills. Italian immigrants moved here starting in 1898, and in 1934 renamed the postoffice after the first bishop of the Roman Catholic Archdiocese of Saint Louis, the Italian-born Joseph Rosati.
The area is part of Missouri's grape growing region and Rosati is well known for its wines. The first Italian immigrants attempted to plant grape varieties from Italy, with no success, and instead grew Concord grapes, used for making juice. In the 1970s, the local growers started replacing these vines with wine grape varieties.