Dalby is a town in the Darling Downs region of Queensland, Australia, and is located approximately west of the state capital, Brisbane, at the junction of the Warrego, Moonie and Bunya Highways. Dalby is the administrative centre of the Western Downs Region and the centre of Australia's richest grain and cotton growing area. At the 2006 census, Dalby had a population of 9,778.
The name of the town is believed to come from the village of Dalby on the Isle of Man and reflects immigration from the Isle of Man in the mid-19th century. The name was apparently chosen by Captain Samuel Perry when he surveyed the settlement in 1853.
Dalby was linked by rail to Ipswich on 20 April 1868.
Dalby was founded in the early 1840s at a place known locally as "The Crossing" on Myall Creek, a tributary of the Condamine River. The first settler was Henry Dennis, who explored the region and chose land for himself and others in the locality. Today an obelisk in Edward Street denotes the location where Dennis camped. A small settlement was founded to assist travellers heading north to nearby Jimbour Station. The explorer Ludwig Leichhardt visited the area in 1844, on his way to Port Essington.