Monodactylidae is a family of perciform bony fish commonly referred to as monos, moonyfishes or fingerfishes.

All are strongly laterally compressed with disc-shaped bodies and tall anal and dorsal fins.

Most are silvery with yellow and black markings; the juveniles are especially attractive, and most species are popular as aquarium fish.

Two extinct species, Psettopsis subarcuatus and Pasaichthys pleuronectiformis, are known as fossils from the Lutetian lagerstatten of Monte Bolca, Eocene, in Italy.

They are hardy and easy to care for, but require brackish water and copious swimming space.