The name Sian is an English baby name. In English the meaning of the name Sian is: Jehovah has been gracious; has shown favour. A Feminine form of John.. From the Old French Jehane. Famous Bearer: American actress Jayne Mansfield.
Find out below. Origin and Meaning of Siann. "Siann" is a name of Welsh origin, and it means "Gods gracious gift. Variant of Sian".
