Wilson was son of Rowland Wilson (died 16 May 1654) of Gresegarth and London, and his wife Mary Tiffin, daughter of John Tiffin of London. His father was a wealthy merchant of the City of London. Wilson was a member of the Worshipful Company of Vintners. During the civil war he was lieutenant-colonel of the orange regiment of the London trained bands, and commanded it in October 1643. He joined the army of the Earl of Essex after the First Battle of Newbury, and took part in the occupation of Newport Pagnell.