Phoenix Sky Harbor International Airport (PHX) serves as a vibrant gateway to the Southwest and a surprisingly affordable launchpad for domestic and even a few international trips. In 2025, you don’t need a fat wallet to fly—several budget airlines operate out of Phoenix, offering rock-bottom base fares that put weekend getaways and cross-country visits well within reach. Frontier Airlines, Allegiant Air, Spirit Airlines, and Southwest Airlines all bring their own flavor of low-cost travel to the Valley of the Sun, while full-service carriers like American Airlines frequently jump into the budget ring with competitive basic economy pricing. This article walks you through the best cheap airlines flying from Phoenix, what each one does differently, how to avoid common fee traps, and where to find the deepest discounts for your next trip.

Key Takeaways for Budget Flying from Phoenix

  • Frontier, Allegiant, and Spirit are true ultra-low-cost carriers with base fares often under $40.
  • Southwest Airlines blends low fares with two free checked bags and zero change fees—rare among budget options.
  • Phoenix-Mesa Gateway Airport (AZA) often undercuts Sky Harbor prices, especially for Allegiant passengers.
  • Packing light and booking early are the two biggest levers for keeping total costs low.
  • Fare alerts and flexible dates unlock $29–$79 one-way deals across multiple airlines.
  • Rental cars and group shuttles can reduce ground transportation expenses once you land.

Overview of Budget Airlines in Phoenix

Budget airlines in Phoenix split operations between two airports: the large, central Phoenix Sky Harbor International Airport (PHX) and the smaller, east-valley Phoenix-Mesa Gateway Airport (AZA). Each airport attracts a different mix of low-cost carriers, and comparing them can easily shave $20–$60 off a ticket. These airlines keep base fares low by unbundling services—you pay only for what you need, whether that’s a checked bag, a soft drink, or the ability to select your seat. For travelers who can pack light and stay flexible, the savings are substantial.

What Defines a Budget Airline?

A budget airline strips away the extras bundled into traditional tickets. No free checked bag, no complimentary meal, and often no advanced seat assignment unless you pony up an additional fee. To cut costs further, these carriers operate single-type fleets (like all-Airbus A320s) and turn planes around quickly at secondary or less congested gates. In Phoenix, you’ll spot ultra-low-cost carriers (ULCCs) such as Frontier, Allegiant, and Spirit, which push a la carte pricing to the extreme. Southwest Airlines, while considered a low-cost carrier, bucks the trend by including two free checked bags and never charging change fees—making it a hybrid that many budget flyers adore.

Benefits of Choosing Budget Carriers

The number-one draw is the fare itself. When you strip everything down, you can routinely find one-way flights from Phoenix to cities like Denver, Las Vegas, Salt Lake City, or San Diego for under $50 if you book early enough. Flash sales often drop prices to $29 or even $19 on routes with strong competition. Beyond sheer price, budget airlines give you total control: if you don’t need a carry-on larger than a small backpack, you don’t pay for one. If you’re fine with a randomly assigned seat, you save another $10–$25 per segment. This customization means a $39 ticket stays $39, while a traveler who wants a roomier seat, a checked bag, and priority boarding can upgrade selectively. The route networks are also expanding—budget carriers now connect Phoenix to smaller cities like Provo, Utah or Appleton, Wisconsin that legacy airlines might skip, giving you direct access to friends and family without a layover.

Major Budget Airlines Operating from Phoenix

Several low-cost carriers have deep route maps out of Phoenix, each with its own pricing model and personality. Here’s a detailed look at the most popular ones for affordable travel in 2025.

Frontier Airlines: Low Fares, High Volume

Frontier Airlines is often the first name that comes to mind when hunting for cheap flights out of Phoenix Sky Harbor. With a modern Airbus fleet and a giant route network, Frontier connects Phoenix to over 50 cities from coast to coast. Regular fare sales can drop one-way tickets to Denver, Las Vegas, or San Diego as low as $29–$49 if you book a month or two out and fly on a Tuesday or Wednesday. To get these prices, you’ll need to fly light: only one personal item that fits under the seat is free. A carry-on bag typically costs $35–$60 each way if added during booking, while a checked bag starts around $30. Seat selection starts at $11, but if you skip it, Frontier assigns one randomly for free. The airline also sells GoWild! Passes that offer unlimited flights for a flat annual fee subject to blackout dates and last-minute booking requirements—ideal for spontaneous travelers based in Phoenix. Frontier’s base fares are hard to beat, but the total cost climbs quickly if you need bags. Packing strategically is the key to keeping that ticket shockingly low.

Allegiant Air: Vacation-Focused and Gateway-Centric

Allegiant Air takes a different approach by operating almost entirely out of Phoenix-Mesa Gateway Airport (AZA), a smaller facility about 30 minutes east of downtown Phoenix. This airline focuses on nonstop leisure routes to smaller, regional airports near popular destinations—think Fort Collins instead of Denver, or St. Petersburg-Clearwater instead of Tampa. Because Allegiant avoids the busiest hubs, airport fees are lower, and that savings is passed along. You can regularly find one-way fares from $33 to $69 to cities like Provo (Utah), Boise, Des Moines, and Tulsa. Allegiant’s fee structure is similar to Frontier’s: a personal item is free, but anything more—carry-ons, checked luggage, seat assignments, even a soda onboard—will cost extra. If you can fit everything into a small backpack, you’ll fly absurdly cheap. Allegiant often bundles flight+hotel+car deals on its website, which can make it one of the cheapest ways to plan a complete vacation from Arizona. Just note that Allegiant flights may only operate two or three days a week on a given route, so flexibility is essential.

Spirit Airlines: Fare Stripping to the Extreme

Spirit Airlines occupies the same ultra-low-cost space as Frontier and serves Phoenix Sky Harbor with a web of routes stretching from the West Coast to the Midwest and beyond. Spirit’s “Bare Fare” covers only a seat and one small personal item; everything from a large carry-on to a cup of water incurs a charge. That said, if you join the $9 Fare Club (about $69.95/year), you unlock significantly lower base fares and discounted bag fees. For a frequent flyer out of Phoenix, the membership often pays for itself in one or two round-trips. Spirit regularly offers $25–$45 one-way fares between Phoenix and cities like Dallas, Chicago, Las Vegas, and Burbank. Like all ULCCs, the best window for booking is 3–8 weeks ahead, and added bags are cheapest when purchased at the time of booking—waiting until the airport can double the fee. Spirit’s loyalty program, Free Spirit, also lets you earn points that can be redeemed for future cheap flights. Visit spirit.com to scout current sale routes.

Southwest Airlines: The Fee-Free Anomaly

Southwest Airlines is a perennial favorite for Phoenix travelers who want low fares without the baggage anxiety. The airline operates a massive operation out of Terminal 4 at Sky Harbor, with nonstop flights to nearly every major U.S. city. While Southwest’s base fares aren’t always the absolute cheapest—you might see $69 one-way to Los Angeles when Frontier lists $39—the total value is often superior. Why? Two checked bags fly free, there’s no fee to change or cancel a flight (you get reusable travel credit), and every passenger receives a complimentary snack and non-alcoholic drinks. Southwest also runs frequent fare sales with tickets as low as $49 one-way on short hauls like Phoenix–Las Vegas or Phoenix–Albuquerque. The boarding process is open seating based on a numbered position, so no seat selection fees. For families, groups, or anyone who hates surprise fees, Southwest is the clear winner. The airline’s Low Fare Calendar tool makes it a breeze to spot the cheapest days to fly, which often land on Tuesdays, Wednesdays, and Saturdays.

American Airlines: A Full-Service Contender for Budget Flyers

While American Airlines is not a low-cost carrier, its dominance at Phoenix Sky Harbor—where it operates as a hub—means it frequently matches or beats budget airline fares on competing routes through its “Basic Economy” product. Basic Economy tickets can undercut Frontier and Spirit by $10–$20 on popular corridors like Phoenix–Dallas or Phoenix–Chicago, and they include a full-size carry-on bag plus complimentary beverages and a snack. The trade-offs: you board last, can’t select a seat in advance (family seating may not be guaranteed), and changes aren’t allowed. Still, for travelers who want a slightly softer ride with an assigned seat at the gate and a carry-on bag included, American’s Basic Economy often delivers more bang for the buck. Checking Google Flights will usually surface American’s cheapest options alongside Frontier and Spirit, making it easy to compare the true total cost.

Tips for Booking the Cheapest Flights from Phoenix

Securing a dirt-cheap ticket requires more than picking the right airline—it’s about timing, flexibility, and knowing a few insider tricks. These strategies work across all budget carriers at both Phoenix airports.

Best Time and Cheapest Month to Fly

Fare data shows that the most affordable months to depart from Phoenix are January, February, and September—outside the summer peak and the December holidays. For summer travel, late August often sees a dip as families return home and leisure demand softens. Booking 6–10 weeks before departure tends to capture the sweet spot for ultra-low-cost carriers, though Southwest’s sales sometimes pop up closer to the travel date. Days of the week matter tremendously: Tuesdays and Wednesdays are consistently cheaper than Fridays and Sundays. Setting up a Google Flights price alert for your desired route will notify you the moment prices drop.

One-Way and Flexible Date Strategies

Instead of defaulting to a round-trip ticket, search for two one-way flights. Sometimes Frontier will be cheapest on the outbound leg, while Spirit wins on the return. Buying them separately can save $20–$60 overall. If your dates are flexible, use the low-fare calendar view on Southwest or Spirit’s website to pinpoint the absolute cheapest days to fly. Early-morning departures (6:00 a.m.) and red-eye returns often carry the lowest price tags. For frequent fliers, consider a seasonal flight pass like Frontier’s GoWild! mentioned earlier, which can cut per-flight costs to pennies on the dollar if you fly often enough.

Comparing Airports for Maximum Savings

Phoenix Sky Harbor (PHX) is the obvious choice for most travelers, but Phoenix-Mesa Gateway Airport (AZA) consistently beats it on price for Allegiant Air flights. Gateway is a smaller, easy-to-navigate airport with cheaper parking rates ($8–$12 a day versus $25+ at Sky Harbor). If you live in Chandler, Gilbert, or Mesa, AZA can be more convenient than fighting traffic into downtown Phoenix. Even if Gateway is slightly farther from your home, the savings on the ticket plus parking can total $80 or more round-trip. Always run a search that includes both airports. A quick check on a comparison site like Kayak or Google Flights with the “Phoenix (PHX)” and “Phoenix-Mesa (AZA)” toggles on will surface the best combined deal.

Mastering Baggage Fees and Packing Light

On Frontier, Allegiant, and Spirit, a carry-on bag can add $35–$60 each way. Checked bags are similarly priced, and skiing equipment or golf clubs cost even more. The single most powerful money-saving move is to travel with only a personal item—a backpack or small duffle that fits under the seat in front of you. Dimensions vary by airline, but a bag measuring roughly 18 x 14 x 8 inches usually passes. Wear your bulkiest clothes on the plane, roll your garments tightly, and use packing cubes to maximize space. If you must check a bag, pay for it online during booking, not at the airport. Airport gate fees for a carry-on can soar to $99 one-way. Southwest remains the refuge for those who can’t pack light, with two free checked suitcases per passenger.

Use Fare Alerts and Price Comparison Tools

Never pay full price without first setting a price alert. Kayak, Google Flights, and Hopper all track fares and send push notifications when prices fall. For Frontier and Spirit, join their email lists to catch limited-time promo codes. Additionally, clearing browser cookies or searching in private mode can occasionally reveal lower fares, though this effect is less consistent than it used to be. A little patience and persistence can uncover hidden deals—especially on routes where multiple budget airlines compete directly, like Phoenix–Las Vegas.

Additional Ways to Save on Phoenix Travel

Flights are just one piece of the travel budget. Once you land, ground transportation and lodging costs can add hundreds to the trip. Here’s how to keep those in check, too.

Car Hire and Transportation Deals

Rental cars at Sky Harbor can be pricey during peak season, but booking 4–8 weeks in advance and using an aggregator like Autoslash often nets a compact car for $25–$35 a day. If you don’t need a car for the entire stay, consider splitting your trip: take a shared shuttle or public light rail from the airport to your hotel (the Valley Metro Rail connects Sky Harbor to downtown Phoenix and Tempe for just $2), then rent a car for a day or two via a neighborhood location to avoid airport concession fees. Many hotels near Gateway Airport offer free parking and shuttle service, which can eliminate rental costs altogether for short getaways. For group travel, a shared ride van like SuperShuttle can be cheaper than two separate ride-share trips. And if you’re staying at a resort, check their airport shuttle policy—some offer complimentary transfers that render a rental unnecessary.

Budget-Friendly Accommodations Near the Airports

For early-morning departures or late-night arrivals, staying the night at an airport-area hotel can keep you rested without busting the budget. Sky Harbor’s western edge has a cluster of motels and chain hotels with rates under $90 a night that include free parking and a shuttle to the terminal. Near Phoenix-Mesa Gateway, options are even cheaper, often dipping below $70 a night. Book a park-and-fly package at these hotels, and you can leave your car there for up to a week for free while you travel, saving the daily airport parking fee.

Stacking Deals on Attractions and Dining

Once you’ve saved on the flight, redirect those dollars to experiences. Phoenix CityPASS bundles admission to top attractions like the Desert Botanical Garden and the Heard Museum at a 40–50% discount. Downtown restaurants frequently offer happy hour specials that turn a $30 dinner into a $15 feast. And many budget airlines have partnerships with local entertainment platforms; for instance, Southwest’s Rapid Rewards portal lets you earn points on hotel bookings and rental cars that can be redeemed for more flights. Stacking these everyday deals with a cheap plane ticket means a full Phoenix vacation never has to feel expensive.

Phoenix remains one of the best cities in America for budget air travel, with a healthy mix of ultra-low-cost carriers and a legacy hub willing to fight on price. By comparing both local airports, choosing an airline that matches your baggage needs, and staying flexible on dates, you can routinely fly out of the Valley for the price of a nice dinner. Whether you’re chasing a quick weekend in Vegas, a family visit in the Midwest, or a spontaneous trip to the coast, the budget airlines in Phoenix have an option that will get you there without emptying your wallet.