William Arnold (24 June 1587 – c. 1676) was one of the founding settlers of the Colony of Rhode Island and Providence Plantations, and he and his sons were among the wealthiest people in the colony. He was raised and educated in England where he was the warden of St. Mary's, the parish church of Ilchester in southeastern Somerset. He immigrated to New England with family and associates in 1635. He initially settled in Hingham in the Massachusetts Bay Colony, but he soon relocated to the new settlement of Providence Plantation with Roger Williams. He was one of the 13 original proprietors of Providence, appearing on the deed signed by Roger Williams in 1638, and was one of the 12 founding members of the first Baptist church to be established in America.