This name is made up of the Old English elements 'cot' "cottage", "hut" and the suffix er.
The Old Norse name is made up of the elements ótti "fear", "dread" and herr "army".
An early Irish record of the name occurs in 1142, when Mac Mic Ottir .i.
Although unprovable, it is possible that both he and they are descendants of the famous Ohthere of Hålogaland, a great Norwegian adventurer who appears to have gone to Ireland.
According to MacLysaght who wrote in the mid 20th century, the Irish surname of Cotter was peculiar to County Cork.