Diomedeoides is a prehistoric genus of seabirds.

The family was in the order Procellariiformes which today is composed of the albatrosses and petrels.

At present it is the only genus in the family Diomedeoididae.

The taxonomy of the family and genus is still in need to revision, and it is likely that the genus name Diomedeoides is actually the junior synonym to Rupelornis (van Beneden, 1871).

[1] Fossils of this genus have been found in the Oligocene and Miocene rocks in Europe and Iran.