Dann is a unisex name of Irish origin, meaning 'dark-haired'. It is often considered a variant spelling of the name Dan, which is derived from the Old Norse name 'Dani', meaning 'from Denmark'. Dann has been used as both a first and middle name in various cultures.
"The popularity of the name Dann peaks in the late 1940s to early 1950s with a high of 71 births in 1957. After that, it declines steadily, with only 5 births per year from 1990 onwards."