St Helens Park draws its name from a Gothic mansion built in 1887 by George Charles Westgarth, a Sydney solicitor.

That honour goes to a farmhouse on Appin Road called Denfield and Curtilage which was built in the 1830s by John Farley of Fisher's Ghost fame.

[2][3][4] By the 1940s, the St Helens Park property had become a fly spray testing laboratory and acquired the local nickname Blowfly Farm.

In 1975, Campbelltown Council designated the area for suburban development and in 1976, it was formally named St Helens Park.

The majority of residents were Australian born (73.3%) and spoke only English (73.1%) although there were substantial minorities speaking Arabic (3.2%), Spanish (1.9%), Samoan (1.7%) and Hindi and Vietnamese (both 1.2%).