|• Density||2,170/km2 (5,630/sq mi)|
|Area||2.4 km2 (0.9 sq mi)|
|Location||16 km (10 mi) from Melbourne|
|LGA(s)||City of Banyule|
Watsonia is a suburb of Melbourne, Victoria, Australia, 16 km north-east of Melbourne's Central Business District. Its local government area is the City of Banyule. At the 2016 census, Watsonia had a population of 5,214.
Watsonia was surveyed by Robert Hoddle in 1838 as part of the parish of Keelbundora, for subdivisional sale as farms. Until the 1870s, much of Watsonia remained part of the vast property holdings of John Brown. The Grace Park area was purchased in 1877 by Frederick Augustus Nell, and then by Frank Watson in the early twentieth century. Watson subdivided the property for housing in 1924. The area remained primarily rural until the 1940s, when property prices became affordable.
Watson and other local landowners paid for the establishment of a railway station in order to attract property buyers. Subdivision commenced with the sale of 44 allotments from the Grace Park Estate, next to the new railway station, in June 1924. Watsonia railway station was named after Mr. F. Watson and was opened on Monday 23 June 1924, between the existing Macleod and Greensborough Stations. It was initially intended to be called Collins. Watsonia Post Office opened around 1934.
78.0% of Watsonia residents were born in Australia. The most common countries of birth other than Australia are England 2.3%, China (excluding SARs and Taiwan) 2.0%, India 1.3%, Italy 1.0% and Sri Lanka 0.8%.
The Simpson Army Barracks, Yallambie was originally known as the Watsonia Military Camp during World War II. This complex was built on the property formerly owned by Ainslie Meares. In 1951, surrounding land was purchased for the extension of the barracks.
Watsonia Library is a bright, modern, well-equipped community library located in Watsonia’s shopping precinct with ample parking and adjacent to the Watsonia train station. It is a branch of Yarra Plenty Regional Library 
The early 2000s punk indie band Klinger mentions a long trip from St. Kilda to Watsonia north in their hit song Hello Cruel World. They also had a much less successful song called Watsonia about the town itself. Lead singer & guitarist, Ben Birchall, lost his virginity in the back of a Corolla here, hence its importance in his song writing.
- Shire of Diamond Valley - Watsonia was previously within this local government area.
- Australian Bureau of Statistics (27 June 2017). "Watsonia (State Suburb)". 2016 Census QuickStats. Retrieved 3 July 2017.
- Banyule City Council - About the City. Retrieved 14 March 2007
- Monash University archives. Retrieved 25 March 2007
- "Advertiser (Hurstbridge, Vic.)". 27 June 1924.
- Phoenix Auctions History, Post Office List, retrieved 2 April 2021
- "Watsonia Station and Shops". North East Link Project. 2019. Retrieved 16 May 2019.
- "Yarra Plenty Regional Library". www.yprl.vic.gov.au. Retrieved 20 May 2019.
- Full Points Footy, Northern Football League, retrieved 15 April 2009