La Quinta Formation is a geological formation in Chiapas, Simojovel in Mexico, deposited during the Late Oligocene into the early Miocene. It is the oldest known formation where Mexican amber can be found. It underlies the Mazantic Shale.
The biota of the La Quinta Formation is primarily compoased of various insects, from wasps such as Hyptia deansi, to ants such as Aphaenogaster praerelicta. It is also home to some early fabacids, like Simojoflorum mijangosii.