The surname Dunn has its origins in Ireland, Scotland, and England. It is derived from the Gaelic word “dun,” meaning fortress or hill. The name was likely given to someone who lived near or worked at a fortress or hill. Dunn is a relatively common surname in the United States, Canada, and Australia. Notable people with the surname Dunn include singer-songwriter Holly Dunn, actor Michael Dunn, and baseball player Adam Dunn.