From an Old Norse place name meaning 'deer wood' or 'doe forest.'
Roscoe traces its origins to the Old Norse ráskógr, a compound of rá (roe deer) and skógr (wood or forest), making it at its heart a name that means 'the deer's forest.' It traveled from Scandinavia into northern England as a place name, became a surname, and then made the transatlantic journey to America, where place names and surnames regularly get redeployed as given names with cheerful disregard for their original function. By the mid-nineteenth century, Roscoe was a fully established American masculine name with a faintly frontier energy.
Roscoe Conkling, the imperious New York senator who dominated Gilded Age Republican politics, gave the name its first major public presence — though his reputation for arrogance meant that legacy was mixed. Far warmer was Roscoe 'Fatty' Arbuckle, the silent film comedian whose physical grace and improvisational brilliance made him one of Hollywood's first genuine superstars before a scandalous 1921 trial (from which he was ultimately acquitted) ended his career and introduced a darker chapter to the name's story. Roscoe Lee Browne, the distinguished actor with his magnificent baritone voice, reclaimed the name for dignity in the latter twentieth century.
Roscoe peaked in American usage in the early 1900s and spent decades in deep hibernation, acquiring the pleasant patina of an old photograph. Contemporary parents drawn to old-fashioned, slightly eccentric names with genuine historical roots have revived it, attracted to its strong consonant structure and its air of a person who builds things, fixes things, and stands their ground.