Not to be confused with the once eastern suburb of Mount Gambier, also called Williamstown.
Williamstown is a small South Australian village on the southern fringe of the Barossa Valley wine-growing region. It is 51 km north east of Adelaide and 16 km south-east of Gawler. Williamstown was originally known as Victoria Creek. The village was laid out in 1858 by Lewis Johnston, or Johnstone, on land he purchased in 1857, and named for his son.
The village has an elevation of 310m and an average rainfall of 680mm. It has a summer average temperature of 31 °C with temperatures often reaching mid 40's, and a winter average temperature of 15 °C, with nights dropping below freezing, which makes the region excellent for the cultivation of fruits, especially grapes in the lower riverine alluvial deposits.
Williamstown was essentially a farming area with sheep and cattle in the early days with fruit orchards, mixed farms and vines. The village also sustained a forestry and lumber industry from the earliest days with three sawmills. Today only a small family owned mill remains with the closure of the two larger mills by 1990. Many residents work in the wine / viticulture industry throughout the Barossa Valley.
In the Australian Federation Year a local hay barn found along Yettie Road (Yatta Creek Road) inhabited by ducks and pigeons was discovered to be the remains of the alleged oldest homestead in South Australia (circa 1821) which has been carefully restored to its former glory.
Springfield Homestead along Springton Road was originally the home of a local land baron pastoralist BJ McLaughlin who was a contemporary of the more famous Australian pastoral entrepreneurs and cattle barons.