Heloecius cordiformis is a species of semiterrestrial crab found in mangrove swamps and mudflats along the east coast of Australia.

Adults of H. cordiformis are around 25 mm (1 in) wide, with a dark purple, mottled carapace.

[3] The purple colour is the easiest of the four to distinguish against the reflectance spectrum of the mudflats on which the crabs live.

[3] Heloecius cordiformis lives from Brisbane (Queensland), along the coast of New South Wales to Port Philip Bay (Victoria), as well as eastern parts of Tasmania.

[5] Heloecius cordiformis is primarily a deposit feeder, sifting through the sediment for organic matter and the detritus from mangroves, but also has large mandibles that it uses to eat larger pieces of plants and animals.