Citharichthys gilberti, the bigmouth sanddab, is a species of flatfish in the large-tooth flounder family Paralichthyidae.

It is native to the eastern Pacific Ocean, in tropical waters ranging from the Gulf of California in the north to Peru in the south.

This demersal fish inhabits the soft bottoms of trawling grounds and bays.

Like the rest of the large-tooth flounders, it has both eyes on the left side of its head.

Citharichthys gilberti is a predator, feeding on large benthic organisms and small fish.