The suburb was originally named Kororoit Creek, after the creek running through the suburb but was renamed after the Melbourne Hunt Club used the area to house their stock of game deer. The original Hunt Club building still stands on Ballarat Road, next to the Deer Park sports oval and is now a community centre. The Hunt Club was opened on Saturday, 11 July 1885. The Post Office opened in 1878 as Kororoit Creek and was renamed Deer Park in 1889.
Following the discovery of gold in Ballarat and Bendigo, to the west, there became a great demand for explosives. Deer Park was chosen as the site of Melbourne’s first explosives factory, commenced by Jones Scott and Co in about 1874 and later reformed as Australian Explosives and Chemical Co, then Nobel (Australasia), Imperial Chemical Industries of Australian and New Zealand (ICIANZ) and most recently Orica.
The site was chosen for its isolation, as it was several miles from the outskirts of Melbourne. The availability of water in Kororoit Creek was also a factor. In the 1920s, Nobel constructed a number of houses around its factory for workers and managers, expanding the former rural village into a substantial industrial suburb.
A fatal accident at the factory in 1923 led to production of Black powder being stopped. In 1928, Imperial Chemical Industries of Australia and New Zealand (ICI, now Orica) took control of the factory. A new Black Powder factory was built in Deer Park in 1936 and enlarged during World War II. Charcoal from Australian timbers also began to be manufactured.
Suburban expansion in the 1920s was slowed during the 1930s depression, but in the post war period the suburb expanded rapidly. With labour shortages and a large demand for products during the post-war boom, ICI commenced housing development in Deer Park to attract workers to the area and many of the surrounding streets are named for localities in the UK, where ICI had operations.