Frankston South, a residential suburb, is immediately south of Frankston and extends (west to east) from Olivers Hill and Mount Eliza to Langwarrin. Its southern limit is Sages Road, Baxter, and it is 43 km south-east of central Melbourne. It was gazetted as a suburb in 1998.
Much of Frankston South is elevated where the Sweetwater Creek descends from Mount Eliza. The creek enters the Frankston Reservoir and then passes around the site of the 1934 Scout Jamboree.
Frankston South and Mount Eliza were included in the Ballanurong pastoral holding acquired by James Davey in 1845. The hilly terrain and absence of reliable water ensured that the Frankston village became the compact place of settlement, and the railway terminus (1882) at Frankston confirmed that situation.
The Port Phillip Bay seafront attracted holiday houses and settlement, and elevated Mount Eliza came somewhat later as a place for holiday homes. Most of Frankston South came after Mount Eliza in that respect. Gumnuts cottage, c1920, on Nepean Highway, Olivers Hill, is an early holiday house designed by Walter Burley Griffin. In 1924 Russell Grimwade built Westerfield on his 45 hectare rural retreat in Robinson Road. Both are heritage listed. Most of Frankston South stayed as open country, remaining so when the scout movement found a location for its 1934-35 jamboree.
Postwar Frankston moved its high school from near the railway station to Towerhill Road, Frankston South in 1958, a year after its neighbour, Overport primary school, opened. Frankston South's population grew steadily in the 1960s, and Overport school had one of Victoria's highest enrolments, 1125, in 1970. A second primary school, Derinya, opened in 1971.
The Frankston South post office opened in 1958, right on the suburb's present boundary with Frankston. Plenty of vacant land lay further afield for some time. Baxter technical school (now Mount Erin college) opened c1976 and the Baptist retirement homes (now Village Baxter) began in 1974. RSL Park war veterans home in Overport Road predated both.
Frankston South has a few local shops. Most shopping involves a car or bus ride to Frankston or Mount Eliza. There are several public reserves: linear parks along Sweetwater Creek; and Delacombe Park, Overport Park and Baxter Park (all with sports facilities). Paratea Park is an intact grassy woodland, and a proposed park around Frankston reservoir is a large natural reserve.
Frankston South's census populations have been: