The Ellimmichthyiformes, also known as double-armored herrings, are an extinct order of ray-finned fish known from the Late Jurassic to the Oligocene. They were the sister group to the extant true herrings, shad and anchovies in the order Clupeiformes, with both orders belonging to the suborder Clupeomorpha. Some studies suggest that the order may be potentially paraphyletic with respect to crown-group Clupeiformes.