What’s the Cheapest Domestic Airline in the U.S.? A Practical Traveler’s Guide
If you’re planning a budget-friendly trip within the United States, one of the first questions you’ll ask is: “Which airline is actually the cheapest?” The answer isn’t as simple as picking one clear winner—but there are consistent patterns that can help you snag the best deal.
The Short Answer
When it comes to ultra-low base fares, Frontier Airlines and Spirit Airlines frequently offer the lowest prices in the U.S. market. These carriers keep ticket costs extremely low but charge extra for bags, seat selection, and other add-ons.
The Top Contenders for Cheapest U.S. Airline
1. Frontier Airlines
Often ranked as the cheapest by cost per seat mile, Frontier offers rock-bottom fares—especially if you travel light and skip the extras.
Best for: Minimalist travelers, weekend trips, spontaneous getaways.
2. Spirit Airlines
Spirit is known for some of the lowest base fares in the country. Though they charge for nearly everything beyond your seat, it’s unbeatable for travelers focused strictly on price.
Best for: Budget-first flyers who pack light.
3. Allegiant Air
Allegiant specializes in serving smaller cities and leisure routes. While flights can be less frequent, the fares are often some of the lowest available.
Best for: Small-city travelers and regional bargain hunters.
4. Avelo Airlines
A newer ultra-low-cost option with extremely competitive fares, especially on routes to smaller or secondary airports.
Best for: Travelers looking for cheap flights to alternative airports.
5. Breeze Airways
Breeze offers modern, low-cost service with affordable pricing and newer aircraft. While not always the absolute cheapest, it provides strong value.
Best for: Travelers wanting comfort on a budget.
6. Sun Country Airlines
A hybrid low-cost carrier, Sun Country provides solid deals—especially for travelers in and out of Minneapolis, its main hub.
Best for: Midwest travelers heading to leisure destinations.
It’s Not Just About the Ticket Price
When choosing the cheapest airline, keep in mind that the base fare is only part of the story. Consider the extra fees for:
- Baggage (carry-on and checked)
- Seat selection
- Airport check-in fees
- Snacks and onboard services
- Departure airports (sometimes farther away)
Sometimes, a slightly higher fare on a carrier like Southwest—where you get two free checked bags—can end up cheaper overall than a low-cost carrier with add-ons.
Which Airline Is Cheapest for You?
For rock-bottom fares: Frontier or Spirit
For cheapest all-in cost (with bags): Southwest
For small-city routes: Allegiant
For newer budget options: Avelo or Breeze
For Midwest flyers: Sun Country
Cheapest Airlines Comparison: U.S. and International
| Airline | Region | Base Fare Level | Baggage Fees | Best Use Case |
|---|---|---|---|---|
| Frontier | United States | Very Low | High | Short domestic trips |
| Spirit | United States | Very Low | High | Price-only travel |
| Southwest | United States | Medium | Low (2 bags free) | Travel with luggage |
| flynas | Saudi Arabia | Low | Medium | Saudi domestic travel |
| Ryanair | Europe | Ultra Low | Very High | Short EU routes |
| AirAsia | Asia | Low | Medium | Regional Asia travel |
Which Airline Is Cheapest by Travel Type?
| Travel Scenario | Recommended Airline | Reason |
|---|---|---|
| No bags, short U.S. flight | Frontier / Spirit | Lowest base fares |
| U.S. flight with luggage | Southwest | Bags included |
| Saudi domestic travel | flynas / flyadeal | Lowest domestic fares |
| European budget travel | Ryanair / Wizz Air | Ultra-low pricing |
| Asia regional flights | AirAsia | Largest network |
Frequently Asked Questions About Cheapest Airlines
Frontier Airlines and Spirit Airlines usually offer the lowest base fares in the U.S., though additional fees may apply.
Southwest Airlines is often the cheapest overall option for travelers who need to check bags, as it includes two free checked bags.
flynas and flyadeal are the cheapest airlines in Saudi Arabia, offering low-cost domestic and regional flights.
Yes. Budget airlines must meet the same safety regulations as full-service carriers.
They can be cost-effective for short and medium-haul routes, but long-haul travelers should consider fees and comfort.
Ultra-low-cost airlines charge separately for carry-on bags, checked luggage, seat selection, and onboard services.
AirAsia leads in Asia, Ryanair in Europe, and flynas in the Middle East.
Tuesdays and Wednesdays are typically the cheapest days to fly.
One-way tickets are often cheaper for domestic flights, while round-trip tickets may be better internationally.
Most budget airlines charge extra for carry-on bags but include a small personal item.
Southwest Airlines has the lowest baggage fees due to its two-free-bags policy.
Last-minute deals exist but are more common on budget airlines and less predictable.
January, February, and September are typically the cheapest months to fly.
Most budget airlines charge change fees, though flexible fares are sometimes available.
Packing light, reviewing baggage rules, and skipping seat upgrades help reduce costs.
Reliability varies by airline and route, with fewer backup flights than major carriers.
Many budget airlines use secondary or alternative airports to reduce operating costs.
Booking early often results in better prices, especially for international flights.
Food and drinks are usually sold separately on budget airlines.
Budget airlines can be used for long-haul travel, but comfort, baggage fees, and flexibility should be carefully evaluated.