Gongylonema is a genus of thread-like nematode that was described by Molin in 1857. It is the only currently valid genus in the family Gongylonematidae, though the mysterious Spiruroides – usually placed in the Subuluridae, which are not closely related to Gongylonema among the Spiruria – might actually belong here. They are parasites of birds and mammals, transmitted by insects (especially beetles). Some 38 species are known, about 12 of which have been recorded in Europe.

Several species are significant parasites of domestic animals, causing gongylonemiasis. Human infection by these nematodes is very rare: since its discovery fewer than 100 people have been reported to be infected with these parasites, always with the species G. pulchrum.