Defence Explosive Factory Maribyrnong, Military heritage site in Maribyrnong, Australia.

Defence Explosive Factory Maribyrnong is a former munitions facility along the Maribyrnong River containing multiple industrial buildings from different production periods. The site includes manufacturing buildings, research facilities, and specialized structures such as blast walls designed for safe handling of explosives.

The land was auctioned as Crown land in 1843 and became Hurtle Fisher's Maribyrnong Stud, with brick stables built in 1888-89; the Cox brothers ran a private racecourse there until about 1901. In the first decade of the 1900s the site was chosen for the Commonwealth's cordite factory, built in 1910, which produced munitions through both World Wars until its closure in 1994. The former factory was added to the Commonwealth Heritage List on 22 June 2004.

The factory employed thousands of workers during World War II, including many women who worked in munitions production. Their labor was essential to Australia's manufacturing capacity during the war years.

The site is closed to the public: Defence considered the 127.8-hectare site surplus in 2010, and a remediation and redevelopment tender closed in July 2024. As of October 2025 some assets there were contaminated with asbestos, so the grounds cannot be toured. The perimeter is bounded by the Horseshoe Bend of the Maribyrnong River and Cordite Avenue.

The site preserves intact structures from different production periods, including specialized blast walls and dedicated cleanways that were once designed for safe explosive handling. These features document the technological standards and safety procedures of the early 20th century munitions industry.