In 1839 Chirnside came from Liverpool on the ship Bardaster. He arrived in Adelaide in January, and Sydney in March of that year. The drought of 1839 adversely affected the sheep he had bought near the Murrumbidgee River, so he joined his younger brother Andrew in Melbourne. 
In April 1842 the brothers established a station in the Grampians, and that same year Thomas acquired a station on the Wannon River, where he was one of the first to employ Aborigines. In the mid-1840s the brothers acquired series of properties in the Western District of Victoria.
The elder Chirnside settled in Werribee, Victoria just before the gold rushes, eventually buying 80,000 acres (320 km²) of land. He built a substantial bluestone house surrounded by a ha ha wall, and later, in the 1870s, the sandstone Italianate Werribee Park Mansion.
On 2 September 1853 he purchased through a government grant Section 14, Parish of Cut Paw Paw, County of Burke. This allotment was 89 acres (360,000 m2), which is now the Melbourne suburb of Kingsville.
Thomas Chirnside was a member of the Philosophical Institute of Victoria from 1857 to 1859 and the Royal Society of Victoria from 1860 to 1866. He was a strict Sabbatarian, allowing no work on his properties on Sundays. He donated an acre (0.4 ha) of land and £100 for the first Presbyterian Church in Werribee, and in February 1884, he laid the foundation stone of the second one. He and Andrew gave £1000 to Ormond College, at the University of Melbourne.
Suffrering from depression, Thomas Chirnside committed suicide in 1887. He was found dead in the garden of Werribee Park with a shotgun lying beside him. Andrew Chirnside inherited the property, but died three years later.
A primary school in Werribee has been named in his honour.
- Hone, J. Ann. "Chirnside, Thomas (1815–1887)". Australian Dictionary of Biography. National Centre of Biography, Australian National University. Retrieved 6 October 2015.
- "Sad Death of Mr. Thomas Chirnside". The Argus. 27 June 1887. Retrieved 6 October 2015.
- McCrory, Phil (designer); Kelleher, Tony (researcher). "The Chirnsides". Archived from the original on 15 December 2003.
- "Thomas Chirnside Primary School". thomaschirnsideps.vic.edu.au/. Retrieved 28 May 2019.
|Library resources about |
Hone, J. Ann (1969). "Chirnside, Thomas (1815–1887)". Australian Dictionary of Biography. National Centre of Biography, Australian National University. Retrieved 19 September 2014. Wool Past the Winning Post by Heather B Ronald A History of the Chirnside Family published by Landvale Enterprises 1978