William Wilton arrived in Australia with his wife on the Hope in October 1838. 
In the 1840's he resided in Newcomen Street next to the Market Square in Newcastle. He was also listed as a Qualified Medical practitioner for the district of Raymond Terrace. He entered into town life at Newcastle. He was one of the residents in 1843 campaigning to make Newcastle a free warehousing port and he chaired a meeting at the Union Hotel in Newcastle on 20th January 1843 on behalf of Alexander Walker Scott who was campaigning for the Legislative Council.
He announced he was moving to East Maitland in April 1845 and commencing medical practice in the cottage adjoining the former residence of Dr. Francis Campbell.  In Maitland he performed post mortems, attended new arrivals in the Immigrants Barracks as well as other duties. In January 1849 he was appointed surgeon for the Maitland Gaol a position he still held in the 1860's. In 1849 one of his duties as surgeon to the gaol was to accompany condemned man George Waters Ward to the gallows.
William Wilton was on the committee for the Newcastle Church Society and on the board of the Church of England School in Maitland.
William Wilton died aged 80 in August 1880. The Maitland Mercury reported his death:
A very old resident of East Maitland died some days ago at his house in Williams Street. Dr. William Wilton had lived 34 years in East Maitland, and had been in the colony 43 years. Previous to leaving England he had practised his profession as surgeon at Gloucester for some years. From the opening of Maitland gaol till about two years back he was medical officer of the establishment; and at last retired from infirmity. Dr. Wilton was scarcely a public man in any sense. He did indeed occupy the position of magistrate, which he accepted with reluctance. He was a fine specimen of the old English gentleman, and his friends were always able to recognise the scrupulous and keen sense of honor which he shared with his class. For some months back Dr. Wilton has been ailing. We have no particulars of his age; he must have been full of years at his death, however.
He was buried in the Glebe burial grounds, East Maitland.