Brannon is of Irish origin, derived from the surname Ó Branáin. It means 'descendant of Branán', with Branán likely being a personal name meaning 'little raven'. The name has gained popularity as a given name in recent years.
The name Brannon experienced a peak in popularity between 1978 and 1980 with eight births each year, but has since declined, with years like 1985 and 1993 seeing only seven births. Overall, there were 116 babies named Brannon from 1975 to 1996.