St Ruth is a locality split between the Western Downs Region and the Toowoomba Region in Queensland, and is located south of Dalby.
The locality was originally called 'St Ruth's' after the parish name, which was in turn named after the St Ruth's pastoral run taken up as part of Cecil Plains pastoral run by Henry Stuart Russell in 1842.
St Ruth’s pastoral run was separated from Cecil Plains in 1842 by Richard Jones, and the name was later simplified to St Ruth. In 1877, 9,000 acres of land was resumed from the St Ruth pastoral run to establish smaller farms. The land was offered for selection on 24 April 1877.
In the 2021 census, St Ruth had a population of 165 people.