The municipality covered an area of 2,611 square kilometres (1,008.1 sq mi), and existed from 1862 until 1995.

It was originally a very large district, including a significant portion of Walpeup, plus Arapiles, Dimboola, Dunmunkle, Kaniva, Kowree and Lowan, centred on the town of Horsham.

By 1900, all of these areas had severed and separately incorporated, and Wimmera's boundaries remained largely unchanged for over 90 years.

The section within the Grampians National Park was transferred to the newly created Shire of Northern Grampians, whilst the Kewell West and Wallup districts were transferred to the newly created Shire of Yarriambiack.

[4] Wimmera was divided into four ridings, each of which elected three councillors: * Estimates in 1958, 1983 and 1988 Victorian Year Books.