Langwarrin is a residential and partly rural suburb 43 km south-east of central Melbourne and 6 km east of Frankston. It was named after the Langwarrin parish, which was named after the Lang Waring pastoral run (1843) which extended from the present suburb to the shores of Western Port Bay at Tyabb.

By the 1880s the pastoral run had reduced to the Langwarrin estate of about 7000 acres. During that decade attention became focused on Langwarrin as the site for a military reserve; the fortification of the entrance to Port Phillip Bay at Queenscliff and Portsea brought the realisation that an invading force would more likely attack at Western Port Bay, taking advantage of the deep water passage at Hastings. A military reserve of 223 hectares was acquired, serviced by a railway from Frankston (1889) for the quick movement of military personnel and supplies.

A township was surveyed in 1887, with a hall and a school. The estate was subdivided for farms, for both orcharding and grazing. The town was a product of the speculative land-boom in the 1880s and failed by 1895. Langwarrin was described in the 1903 Australian handbook:

A new Langwarrin emerged, about 3 km east of the railway station, where a school opened in 1907. Between the railway line and the school Cruden Farm on Cranbourne-Frankston Road was established in 1928 by the Herald Sun executive, Keith Murdoch, as a gift to his bride, Elisabeth. The farm and family retreat has become an outstanding garden, retaining landscape design by Edna Walling.

Langwarrin's public institutions were distributed along Warrandyte Road along the east side of the military reserve: general store and post office, Anglican church (1938), CFA station, State school (520 pupils, 2014) and ending at Lloyd Park and the public hall. The store and CFA station have been moved, but the Elisabeth Murdoch College (1974) and a Catholic primary school (1978) have Warrandyte Road addresses.

By 1966 Langwarrin had about 1000 house lots for sale or built on, mostly north-east of the Cranbourne Road/McClelland Drive intersection. The name of the drive came from the McClelland gallery (1971), financed by local benefactors and later supplemented by the Elisabeth Murdoch sculpture foundation (1979).

During the 1990s Langwarrin's housing area spread eastwards. Langwarrin Park primary school opened in 1989 (688 pupils, 2014) and Woodlands primary school opened in c1996 (793 pupils, 2014). The shopping centre west of Warrandyte Road was overtaken by the Gateway drive-in centre on the Cranbourne Road and Langwarrin Plaza further east.

Military exercises ended in 1980 and the land was sold to the State Government in 1982 for a flora and fauna reserve. The site is heritage listed. Cruden Farm is a jewell in the open gardens crown and Dame Elisabeth passed away in 2012 after her 103rd birthday.

South of the military reserve, once part of Baxter, the area is now Langwarrin South. Mostly rural, it includes Joan and Daryl Lindsay's heritage listed Mulberry Hill property, Woodleigh School and the Bayside Christian College.

Langwarrin's census populations have been:

census date population
1911 175
1921 218
1933 358
1954 577
1961 844
2001 17,244
2006 19,823
2011 21,371