The name Barnes has three possible origins. One is English where the British surname Barnes comes from a significant barn in the local region. Another is Scottish, where in Aberdeenshire, Scotland, the parish of Barnes got its name from the Gaelic word "bearn" which means "gap".

The third and most likely origin is Irish, possibly Anglo-Saxon or Norse. The name seems to be derived from the Old English word "beorn"
Surname Origin: English, Scottish, Irish Definition: Of the barn (barley house), this British surname is often derived from a significant barn in the local region. A possibly alternative origin can be suggeste by the parish of Barnes in Aberdeenshire, Scotland which derives its name from the Gaelic word "bearn," meaning "gap." There are multiple theories of the origin of the surname. It is variously suggested to be of Anglo-Saxon, Norse, or Irish provenance. According to one etymology, the name is derived from Old English beorn which means warrior, which is in turn of Old Norse origin. In another account, it was simply an occupational name for a person who works in a barn, or a topographic name for a person who lives near a barn.