Orestias is a genus of pupfish. Older systematics classified them into the own family Orestiidae. They are found in lakes, rivers and springs in the Andean highlands of South America, and several species are considered threatened. They are egg-laying fish that feed on small animals and plant matter. The largest species can reach a total length of 27 cm (10.6 in), but most remain far smaller. Their most characteristic feature is the absence of the ventral fin, although this is shared by a few other pupfish. Despite their moderate to small size, they are important to local fisheries and a few species are farmed.

Several species are locally and colloquially known as carache. The name of the genus is a reference to Orestes, a Greek mythological character who Valenciennes described as the "nymph of the mountains".

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