The Borough of Toowoomba was proclaimed on 19 November 1860 under the Municipalities Act 1858,[1] a piece of New South Wales legislation inherited by Queensland when it became a separate colony in 1859.

[6][7] On 19 March 1949, following a major reorganisation of local government in South East Queensland,[8] Toowoomba grew its area to include parts of the Shires of Highfields and Drayton.

In 2006 the Mayor Dianne Thorley proposed a controversial plan to recycle sewage into Cooby Dam which is used for drinking water.

The federal government agreed to provide partial funding subject to a number of conditions including a requirement to hold a referendum on the issue.

On 15 March 2008, under the Local Government (Reform Implementation) Act 2007 passed by the Parliament of Queensland on 10 August 2007, the City of Toowoomba merged with the Shires of Cambooya, Clifton, Crows Nest, Jondaryan, Millmerran, Pittsworth and Shire of Rosalie to form the Toowoomba Region.