Osteoglossiformes /ˌɒstiːoʊˈɡlɒsɪfɔːrmiːz/ (Greek: "bony tongues") is a relatively primitive order of ray-finned fish that contains two sub-orders, the Osteoglossoidei and the Notopteroidei.

They are found in South America, Africa, Australia and southern Asia, having first evolved in Gondwana before that continent broke up.

[2] In 2008, several new species of marine osteoglossiforms were described from the Danish Eocene Fur Formation, dramatically increasing the diversity of this group.

This implies that the Osteoglossomorpha is not a primary freshwater fish group with the osteoglossiforms having a typical Gondwana distribution.

In other respects, osteoglossiform fishes vary considerably in size and form; the smallest is Pollimyrus castelnaui, at just 2 centimetres (0.79 in) long, while the largest, the arapaima (Arapaima gigas), reaches as much as 2.5 metres (8.2 ft).