Cheap Mexico airlines are easy to find, with Avolar, Azteca, Click, Interjet, vivaAerobus, or viva Aerobus, and Volaris offering competitive and inexpensive fares.
More cheap Mexico airlines will probably be on the way as Mexico privatizes major airline AeroMexico. The cheap Mexico airlines below are like Southwest in the U.S. and budget airline easyJet in Europe -- cheap airfares to sometimes (to Norte Americanos) obscure or remote airports, though some, like RyanAir's vivaAerobus, will be serving a few U.S. cities, too.
Check out the list of current cheap Mexico airlines below and bear in mind that you may have to use Mexico buses to get around and to the airports, or that the buses may (likely) provide cheaper long-haul Mexico travel than flying within Mexico. Most sites are in Spanish and the deals are very hard to find -- persist and it may be worth it. Different airlines serve different hubs, meaning you may have to search a couple of airlines to put together the ultimate route you want.
- Aviacsa - Aviacsa's hub is in Mexico City and it's got one of the larger destination maps among the budget Mexico airlines. Aviacsa's site has an English section.
- Click - Click Mexicana serves many very cool and somewhat less touristy areas, like beach resort Huatulco (south of Oaxaca city) and colonial Merida (play a few days, then drive to Cancun and Tulum), with often very cheap Mexico airfare specials.
- Interjet - Interjet offers Veracruz, Tampico, and Monterrey routes among its cheap Mexico airfares.
- Viva Aerobus - RyanAir's Mexico airline started offering cheap Mexico airfare in September 2006. RyanAir is the cheap European airline champ based in Ireland and will be teaming with Mexico's IAMSA bus company for the Ryanair Mexico airline.
- Volaris - Volaris airline is one of the cheap Mexico airlines with a Bajio Leon (San Miguel de Allende) routes, as well as a Tijuana-Cancun route.
You can always cobble together a cheap Mexico airfare using a US airline sale or a student airfare to a US-Mexico border city like San Diego (take the bus to Tijuana) or Juarez, then grab a cheap Mexico airfare from one of the affordable Mexico airlines listed above.