Thomas Gill arrived as a free passenger on the Royal George in November 1821.
The new Governor Major General Sir Thomas Brisbane with his family and suite came on the Royal George...upon the vessel coming to an anchor in Sydney Cove, a salute of 19 guns was fired from Dawes' Battery; and immediately afterwards HIs Honor Lieutenant Governor Erskine proceeded on board, to pay his respects to His Excellency and to greet him on his safe arrival in New South Wales. The Royal George also brought a valuable and extensive assortment of merchandise for Berry and Wollstonecraft. Passengers included Mr. Murdoch, Mr. Ross, Mr. Robert Crawford, Mr. Cavenaugh, Mr. and Mrs. Acres, Mr. Bunker, Mr. McLeod, Mr. Weaver and 14 steerage passengers. Mr. Russell, a cabin passenger died on the voyage. 
After a Memorial to the Governor requesting a grant of land, Thomas Gill was granted 640 acres in 1825. He selected this land on the Williams River.
He didn't immediately occupy this grant as he was employed as assistant Commissariat Clerk at Newcastle.
He drowned in the first branch of the Hunter River on 15th October 1826 by falling over the side of his boat. His daughter Isabella Maria was just four months old.
In 1838 his 640 acre grant was offered for sale - A most important and valuable portion of land on the navigable bank of the Williams River within about three miles of its junction with the Hunter. Six hundred and forty acres as originally charted and granted by the Crown to Mr. Thomas Gill, situated in the parish of Thornton, and County of Gloucester, being bounden on the West by the Williams River about a mile and a quarter; on the north by Mr. Jacob Newton's Farm; on the East by the celebrated Irrawang Vineyard and Pottery of James King Esq., and on the South by Mr. James Thew's Grant; a most valuable Lagoon is on the south eastern part of it. - 
In 1845 James King of Irrawang made a claim for the Deed of Grant having purchased the land from the heirs of Thomas Gill.
 Sydney Gazette 10 November 1821
 Sydney Gazette 4 January 1838 n 1845
 Colonial Secretary's Correspondence, Memorials To The Governor, 1810-1826