Austrocoenagrion is a monotypic genus of damselflies belonging to the family Coenagrionidae. The single species of this genus, Austrocoenagrion lyelli, is commonly known as a swamp bluet.
Austrocoenagrion lyelli is a medium-sized damselfly, the male is bright blue with black markings. It is found in south-eastern Australia, where it inhabits streams, pools and lakes.
The species, Austrocoenagrion lyelli, was originally described as Agrion lyelli by Robin Tillyard in 1913. It was later transferred to the genus Coenagrion, where it was known as Coenagrion lyelli..
Agrion brisbanense, from Brisbane, described by Tillyard in 1917, was subsequently found to represent the same species. It is now treated as a synonym.
The species is currently placed in the genus Austrocoenagrion.