Australian Railway Historical Society

The Australian Railway Historical Society (ARHS) aims to foster an interest in the railways, and record and preserve many facets of railway operations. It had divisions in every state and the Australian Capital Territory, although the ACT division was wound up in 2016, along with the Victorian division in 2020. Since 1967, when each division incorporated, the state divisions have operated as separate entities. Each still trades under the ARHS brand, except in Western Australia, where the division is called Rail Heritage WA. The Australian Railway Historical Society (ARHS) was founded in Sydney in 1933 as The Australasian Railway and Locomotive Historical Society. The Society's name was changed to the present form in 1952.

More information on the Wikipedia page - there are links to the various states' societies.