Hassalstrongylus forresteri is a nematode worm of the genus Hassalstrongylus that infects the marsh rice rat (Oryzomys palustris) in the United States.

It was first described as Hassalstrongylus musculi by Marie-Claude Durette-Desset in 1972, but she later recognized it as a different species, H. forresteri.

[1] The females cannot be distinguished from those of the other species in the marsh rice rat, H. musculi and H. lichtenfelsi.

[2]