Allegiant has cheap flights to Provo, UT from Santa Ana/Orange County, CA; Orange County/LA, CA; John Wayne/Anaheim, CA; Austin, TX; Chicago, IL; Portland, OR; and Las Vegas, NV. There are a few more places as well.

Low Cost Flights from Provo as low as $34 | Allegiant Air

Breeze has cheap flights to Provo, UT from San Francisco, CA; San Bernardino, CA; Orange County/Anaheim, CA; and Hartford, CT. There are also a few more places on their website.

Breeze Airways (flybreeze.com)