The cheapest flight a Cancún you can get by boooking 2 days before departure.
The most popular airlines on the route Quito - Cancún: American Airlines (AA), Avianca (AV), Copa Airlines (CM).
The cheapest flights you can book on the route Mariscal Sucre (UIO) - Cancún Intl Airport (CUN).
There is no direct flight on the route desde Quito a Cancún
The shortest flights with change last about 7h 18min.