The surname Rosi is a topographic surname, which was given to a person who resided near a physical feature such as a hill, stream, church, or type of tree. Habitation names form the other broad category of surnames that were derived from place-names. They were derived from pre-existing names for towns, villages, parishes, or farmsteads. Other local names are derived from the names of houses, manors, estates, regions, and entire counties. As a general rule, the greater the distance between an individual and their homeland, the larger the territory they were named after. For example, a person who only moved to another parish would be known by the name of their original village, while people who migrated to a different country were often known by the name of a region or country from which they came. In Scotland, the island of Rousay is located on the Orkney Islands and dates back to Neolithic times. The island's spelling evolved from "Rollesay" in the 14th century and "Rowsay" in the 16th century. But before migrating to Scotland, the Rosi family lived in Normandy at the village of Rosay.

The surname Rosi was first found in Norfolk, where they were Lords of the Manor of Waterden and West Rudham where Lambert de Rossei was an under tenant to Earl Warren. They were originally from Rosay, Seine-Inf, arrondisement of Dieppe, in the canton of Bellencombre. Descended was Lambert's son, Walkelin who held Castle Acres, and then succeeded by Ralph de Rosei about 1270. They seemingly moved north to Fife where they were granted the lands of Rossie near Montrose.

Early History of the Rosi family

Rosi Spelling Variations

Early Notables of the Rosi family (pre 1700)

Migration of the Rosi family to the New World and Oceana

Contemporary Notables of the name Rosi (post 1700)