Thomas Grayson (Generation three) was born in 1852 at Boconnel, Co. Armagh, Ireland. He married Elizabeth Mawhirt, daughter of John James Mawhirt and Elizabeth Turkington, on 14 May 1873 at Seagoe parish, Ireland. Thomas and Elizabeth came to Queensland in the Great Queenslander , eventually going to Killarney, where they resided for the rest of their lives. When Thomas first went to Killarney he was employed by the late Mr.Theo.Howell on Melrose station. He was one of the original settlers of the homesteads opened up at Killarney in the eighteen seventies. Thomas died on 13 Oct 1931 at Killarney, Qld.
Thomas and Elizabeth were described as weavers on their marriage certificate while their fathers James and John were described as farmers.