Jannali is a suburb in southern Sydney, in the state of New South Wales, Australia. Jannali is located 28 kilometres south of the Sydney central business district in the local government area of the Sutherland Shire. The majority of land use in Jannali is residential and bushland reserve, while the suburb is bisected by the north–south railway line. The majority of Jannali’s enterprises are located close to the suburb’s railway station.

Jannali railway station is on the Illawarra line of the Sydney Trains network. Access to the platform for city-bound trains and the railway ticket office is off Janalli Avenue, while access to the platform for south-bound trains is off Railway Crescent.