Kids eat free! Kids stay free! Kids admitted free!

From restaurants like Denny's to Holiday Inns to county fairs, someone is frequently offering the chance to bring the little ones along without paying for them. So it’s only natural to ask: Are there kids-fly-free airlines?

For children too old to spend the whole flight in your lap, the short answer is no. There are also not many discounted kids' fares. After all, a plane seat has the same value to the airline no matter the age of the passenger sitting in it.

But which airline has the cheapest child fares? That would be Frontier Airlines. The airline boasts a Kids Fly Free program, but these deals are only available to people who pay for annual Discount Den memberships.

If you have very small children, fly Frontier often or if you can find an applicable kids-fly-free promotion, you just might get your kids on the plane at a significant discount.

On which airlines do kids fly free?

Only Frontier Airlines offers an ongoing program where kids can fly free (more on that later).