How early should I be at the Quito Airport?

For domestic flights, locals usually arrive ONE hour before take off. Security is quick and the airport is quite small which are things to consider.

For international flights the airlines say be there 3 hours before, but most locals find that to be too much. Two hours before take off is usually plenty, especially in the early morning.

For GALAPAGOS flights, you should allow a bit more time than your normal domestic flight, say 1.5 to 2 hours before take off.