A variant surname I found is Onn, mostly found in Lincolnshire, particularly in regions called North East Lincolnshire and North Lincolnshire, which is the same spot where the surname Own is most concentrated at. This means that most likely the surname Own and Onn are variants of each other. The surname Own/Onn could possibly be of Welsh origin, variants of Owen, but based on my research, it is on the bottom of my list of likely possible origins of this surname Own and Onn. I think this surname could either originate from English surname Ann, or maybe the surname Own/Onn is of Scandinavian origin. Old Norse?