Myrmecium may refer to:

Myrmecium (spider), a genus of ant-like spiders from South America (Castianeirinae) Myrmecium (sponge) (Goldfuss), a genus of extinct Calcareous sponges Myrmēkion, an ancient Greek town at Crimea

See also Myrmecia (disambiguation) Myrmaecium, a genus of fungi