The Shire of Serpentine-Jarrahdale is a local government area in the outer southeastern metropolitan area of Perth, the capital of Western Australia, and has an area of 905 square kilometres (349 sq mi) and a population of 32,173 as at the 2021 Census. Despite being named after two towns in the area, neither Serpentine nor Jarrahdale function as either the Shire's largest settlement (Byford) or the seat of government (Mundijong).

The Serpentine-Jarrahdale Road District was established on 8 August 1913 with the amalgamation of the Serpentine Road District (1894) and Jarrahdale Road District (1902).^[2][3][4]

On 1 July 1961, it became a Shire following the passage of the Local Government Act 1960, which reformed all remaining road districts into shires. On 17 June 1977, it acquired Byford from Shire of Armadale–Kelmscott.^[2]

Following the 2021 Shire of Serpentine-Jarrahdale local government election, councillor for the North Ward, Rob Coales, led calls for an investigation into fraud during the election. The motion was passed unainmously.^[5]

From the 2021 census, the shire had a population of 32,173, with 2.9% being Indigenous. Compared to the national and state median age of 38, the shire's median was younger at 33.^[6]

The suburbs, towns and localities of the Shire of Serpentine-Jarrahdale with population and size figures based on the most recent Australian census:^[16][17]

• 1911 populations were: Serpentine RD 328; Jarrahdale RD 1,126.
• The 1976 figure above, reported from the 1978 year book and 1981 census, is the figure after the addition of 1,634 residents living in Byford and nearby areas, which occurred in 1977.

As of 2024^[update], 112 places are heritage-listed in the Shire of Serpentine-Jarrahdale,^[31] of which five are on the State Register of Heritage Places.^[32]