Which Airline Has the Cheapest Pet Fees in 2026? A Complete Airlines Comparison

Flying with a pet can quickly become expensive if you don’t understand how airline pet fees work. While many airlines advertise similar prices, the true cost of flying with a pet depends on whether the pet travels in the cabin or cargo, how strict the airline is with carriers, and whether the route actually allows pets. This is why travelers frequently search “Which airline has the cheapest pet fees?”—they want the lowest price that actually works.

Some airlines offer low advertised fees but restrict pets to cargo only. Others allow in-cabin pets but charge significantly more. The cheapest airline is not always the best choice unless you understand the trade-offs involved. This guide compares all major U.S. airlines, explains which ones are genuinely affordable for pet owners, and helps you decide which airline makes the most sense for your situation.

Which Airlines Offer the Cheapest In-Cabin Pet Fees in the U.S.?

For travelers looking for the absolute cheapest in-cabin pet fees in the United States, Southwest Airlines and Delta Air Lines consistently rank at the top, with pet fees typically around $95 one way for small cats and dogs traveling in the cabin. These two airlines stand out not only because of the low price, but also because they allow pets to remain under the seat with their owners on most domestic routes, making them the most practical low-cost options among major carriers.

Close behind are budget airlines like Frontier, which charges around $99 one way for in-cabin pets but comes with stricter carrier rules and fewer route options. Some airlines, such as Allegiant, advertise even lower fees—around $50—but those rates apply only to pets traveling as cargo, not in the cabin. As a result, for travelers prioritizing in-cabin pet travel on major U.S. airlines, Southwest and Delta remain the cheapest and most reliable choices, even as fees and policies continue to evolve.

Cheapest In-Cabin Pet Fees (Best for Most Travelers)

In-cabin pet travel is the most popular option because it allows pets to stay with their owners, reduces stress, and avoids cargo-related risks. The airlines below offer the lowest in-cabin pet fees while still allowing pets to travel under the seat.

Southwest Airlines – ~$95 Each Way

Southwest Airlines is widely considered the cheapest major airline for in-cabin pet travel. The airline charges about $95 one-way for small cats and dogs and keeps its pet policy relatively straightforward. There are no complex fare tiers, and the booking process is simple compared to many legacy carriers.

What makes Southwest especially attractive is that its low pet fee is paired with free checked bags, which helps offset the cost of bringing a pet carrier onboard. However, Southwest operates domestic flights only, so it is not an option for international pet travel.

Best for: Small pets on domestic U.S. routes

Not ideal if: You need international travel or assigned seating.

Delta Air Lines – ~$95 Each Way

Delta matches Southwest with an in-cabin pet fee of approximately $95 on many U.S. routes, as well as select short international flights. Delta is often considered the most balanced option because it combines a low fee with a large route network and consistent enforcement.

Delta does strictly limit the number of pets per flight and enforces carrier fit at check-in, but travelers who plan ahead usually have a smooth experience. For those who want affordability and flexibility beyond domestic routes, Delta is often the best compromise.

Best for: Domestic travel and nearby international destinations
Not ideal if: You need guaranteed pet availability on busy routes

Frontier Airlines – ~$99 Each Way

Frontier Airlines offers one of the lowest pet fees among ultra-low-cost carriers. At around $99 each way, it is cheaper than most legacy airlines, but travelers must accept Frontier’s no-frills model.

Frontier enforces strict carrier size rules, and additional charges for seats and bags can offset the savings if you’re not careful. While the pet fee itself is competitive, the overall experience may feel restrictive for first-time pet travelers.

Best for: Short trips where cost is the top priority
Not ideal if: You want flexibility or onboard comfort

Alaska Airlines – ~$100 Each Way

Alaska Airlines charges about $100 for in-cabin pet travel and is often praised for being consistently pet-friendly. Although slightly more expensive than Southwest or Delta, Alaska’s clear policies and reliable service make it a strong option, especially on West Coast routes.

Alaska is not always the cheapest, but many travelers choose it for peace of mind rather than saving a few dollars.

Best for: West Coast and Alaska routes
Not ideal if: You’re strictly chasing the lowest price

Budget Airlines With Low Fees (But Important Trade-Offs)

Some airlines advertise very low pet fees, but the details matter.

Allegiant Airlines – $50 (Cargo Only)

Allegiant’s $50 pet fee often appears in searches as the cheapest option, but there is a major limitation: pets are not allowed in the cabin. This fee applies only to pets traveling as cargo.

For travelers who are comfortable with cargo transport and meet all eligibility requirements, Allegiant can be inexpensive. For most pet owners who want in-cabin travel, the low price is misleading.

Best for: Cargo-only pet travel on short routes
Not ideal if: You want your pet in the cabin

Spirit Airlines – ~$125 Each Way

Spirit allows in-cabin pets for around $125 each way. While this is higher than Southwest or Delta, it remains cheaper than American or United. However, Spirit’s additional fees for bags and seating can make the total cost higher than expected.

Spirit may still work for travelers who understand the fee structure and pack light.

Best for: Budget travelers with small pets
Not ideal if: You dislike add-on pricing

Major Airlines That Are Not the Cheapest (But Often Asked About)

These airlines are frequently searched but are rarely the cheapest choice.

JetBlue Airways – ~$125 Each Way

JetBlue charges about $125 for in-cabin pets. While the airline offers a more comfortable experience than many budget carriers, the higher fee makes it less competitive for travelers focused purely on cost.

American Airlines – $150 Each Way

American Airlines has one of the highest in-cabin pet fees at $150 each way. While it offers extensive domestic coverage, the cost and strict enforcement make it less appealing for budget-focused pet travel.

United Airlines – $150 Each Way

United’s pet fee is similar to American’s. Combined with route restrictions and limited pet slots, United is usually not the cheapest option for flying with pets.

Cheapest In-Cabin vs Cheapest Overall: What Most Travelers Miss

This is where many travelers get confused. The cheapest advertised pet fee is not always the best choice.

• Cheapest in-cabin: Southwest & Delta (~$95)
• Cheapest advertised: Allegiant ($50, cargo only)
• Best balance of price & flexibility: Alaska Airlines

For most pet owners, in-cabin travel is worth the slightly higher fee.

Final Verdict: Which Airline Has the Cheapest Pet Fees?

For travelers flying with small pets in the cabin, Southwest Airlines and Delta Air Lines offer the cheapest and most practical pet fees at around $95 each way. While Allegiant appears cheaper on paper, its cargo-only policy limits its usefulness. Ultimately, the cheapest airline depends on whether you prioritize in-cabin travel, route availability, or absolute lowest cost, but Southwest and Delta remain the best overall options for most pet owners.

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