The Burnett River forms the southern boundary of the locality at an elevation of 100 metres (330 ft) while Reid Creek (a tributary of the Burnett River) forms the eastern boundary. The land in the locality rises toward the north with two peaks: Mount Gayndah in the south of the locality at 364 metres (1,194 ft) and an unnamed peak in the south-west at 340 metres (1,120 ft). A number of creeks rise in the locality and flow south or east to become tributaries of the Burnett River or Reid Creek respectively.
The more mountainous areas are undeveloped land. The predominant land use is grazing with some irrigated farming near the Burnett River.
The locality takes its name from the Dirnbir railway station (Mungar Junction to Monto branch railway. The Queensland Railways Department named the station on 28 February 1913 using an Aboriginal word meaning grey ironbark tree.) on the now closed
Dirnbir State School opened circa 1915 and closed circa 1933.
- Australian Bureau of Statistics (27 June 2017). "Dirnbir (SSC)". 2016 Census QuickStats. Retrieved 20 October 2018.
- "Dirnbir - locality in North Burnett Region (entry 45343)". Queensland Place Names. Queensland Government. Retrieved 11 June 2019.
- "Queensland Globe". State of Queensland. Retrieved 31 July 2019.
- "Dirnbir - railway station in the North Burnett Region (entry 10179)". Queensland Place Names. Queensland Government. Retrieved 31 July 2019.
- "RAILWAY STATIONS". Daily Standard (376). Queensland, Australia. 26 February 1914. p. 2 (SECOND EDITION). Retrieved 31 July 2019 – via National Library of Australia.
- "Mount Debateable - railway station in the Burnett Region (entry 23010)". Queensland Place Names. Queensland Government. Retrieved 31 July 2019.
- Queensland Family History Society (2010), Queensland schools past and present (Version 1.01 ed.), Queensland Family History Society, ISBN 978-1-921171-26-0