Are Pets Allowed On Allegiant Airlines? | Carrier Size Rules

Yes, small domestic dogs and cats can fly in the cabin in an approved carrier for a per-segment fee on eligible routes.

Flying with a pet on a low-cost airline can feel like a coin toss: will the carrier fit, will the gate agent accept it, will you get to the seat and find the space is tight? This page breaks down Allegiant’s pet rules in plain English—carrier measurements, fees, where your pet stays, and how to avoid surprises at the airport.

Allegiant’s pet program is simple on paper: cats and dogs only, in the cabin only, inside a closed carrier that goes under the seat. The details are where plans can wobble.

What “Pets Allowed On Allegiant Airlines” Means In Practice

Allegiant accepts household cats and dogs as pets, and they travel with you in the main cabin. There’s no cargo option for pets. So if your animal can’t ride in a carrier under the seat, Allegiant won’t be a fit for that trip.

The carrier is treated as a carry-on item. That changes how you pack. Most travelers bring one personal item plus the pet carrier, then skip a larger carry-on unless they’ve paid for it and can still stay within Allegiant’s item limits.

Pet space can be limited on a flight. That means you’ll want to add the pet during booking, not show up hoping to pay at the counter. If you wait, you may be turned away even if you’re willing to pay.

Are Pets Allowed On Allegiant Airlines? Cabin Basics

For pet travel, Allegiant is focused on one setup: the animal stays inside a leak-proof carrier that fully closes, and the carrier stays under the seat in front of you during taxi, takeoff, and landing. On most flights, that’s also where the carrier stays for the rest of the trip.

Your pet should be able to stand and turn around inside the carrier without being forced into a crouch. If the carrier bulges out past the size limits, you’re taking a risk at the gate.

Pets Allegiant Accepts

• Domestic dogs
• Domestic cats

Other animals—birds, rabbits, reptiles, rodents—aren’t accepted as pets on Allegiant flights.

Routes Where The Pet Option Applies

Allegiant’s standard pet-in-cabin option is set up for flights within the contiguous 48 U.S. states. If your itinerary includes places with tighter animal entry rules, you’ll need to confirm the flight is eligible and that you can meet local entry requirements.

Booking The Pet Spot And Paying The Fee

Allegiant charges a pet-in-cabin fee per person, per segment. A “segment” is one flight leg. If you connect, you pay the fee on each leg. The easiest way to avoid confusion is to count flights, not travel days.

You’ll see the pet-in-cabin charge at checkout when you add a pet. The fee is billed per segment, so connecting itineraries stack the charge.

If you’re traveling with another adult, each passenger can usually bring one carrier, as long as you meet all limits and the flight still has pet spots open. If you’re traveling solo, plan on one carrier.

What To Bring To The Airport

Most of the time, you won’t need a health certificate for a typical domestic pet trip, but rules can change by destination, and some localities ask for proof of rabies vaccination. Check the requirements for where you’re going and where you’re coming back from.

Bring a copy of vaccination records on your phone and a paper copy in your bag. If something goes sideways with your battery or signal, paper saves the day.

Carrier Rules That Gate Agents Actually Check

Carrier size and closure are the two points that get looked at most. Allegiant publishes separate maximum dimensions for soft-sided and hard-sided carriers. Soft carriers are popular because they flex a bit under the seat, but the external measurements still need to be within limits.

Allegiant’s “Traveling with Pets” page spells out the carrier dimensions, the requirement for an enclosed leak-proof carrier, and the rule that the carrier must fully close. Traveling with Pets is the cleanest official reference to keep bookmarked.

Soft-Sided Carrier Maximum

A soft-sided carrier may be no larger than 18 in. long × 12 in. wide × 11 in. high. Measure the outside, including any firm base, rails, or pockets that stick out.

Hard-Sided Carrier Maximum

A hard-sided carrier may be no larger than 17 in. long × 11 in. wide × 10.5 in. high. Hard carriers don’t flex, so if you’re near the limit, measure twice.

How Many Pets Per Carrier

Allegiant allows up to two pets in one carrier. That only works when the animals are small and calm together. If they’re stressed or crowding each other, the safer choice is one pet per carrier.

Seat, Boarding, And In-Flight Rules

Your carrier goes under the seat in front of you. That can limit where you can sit. Seats with no under-seat space, or seats where the space is blocked by equipment, can be a problem. If you pick a seat that won’t fit the carrier, you may be moved.

Keep your pet inside the closed carrier while you’re in the airport, on the jet bridge, and on the plane. If your pet needs a break, use a pet relief area before you board, then line the carrier with an absorbent pad for the flight.

Plan your boarding flow. Put the carrier on the floor early, then slide it under the seat once you’re settled. If you wait until the aisle is full, you’ll feel rushed.

Allegiant Airlines Pet Rules At A Glance

Rule Area	What Allegiant Requires	Practical Tip
Pet types	Domestic dogs and cats only, in cabin	Leave ESA paperwork out of it; pets follow pet rules
Cargo transport	No pet transport in the cargo hold	If your pet can’t fit under-seat, pick another airline
Soft carrier size	Up to 18″ × 12″ × 11″ (external)	Measure pockets and firm frames, not just the fabric panel
Hard carrier size	Up to 17″ × 11″ × 10.5″ (external)	Hard shells don’t flex, so stay under the limit
Carrier style	Enclosed, leak-proof, fully closes	Zippers should meet; test the closure before travel day
Pets per carrier	Up to 2 pets in one carrier	Only pair pets that ride calmly together
Carrier counts as	A carry-on item toward your allowance	Pack lighter, or prepay for more baggage items
Fee	Charged per segment (each flight leg)	On connections, budget the fee twice
Under-seat rule	Carrier stays under the seat in front of you	Choose a seat with full under-seat space

If you want to confirm the current amount before you book, Allegiant lists it under Pet-in-Cabin (per person, per segment) on its optional services page.

Service Animals And How They Differ From Pets

Service animals are handled under a different set of rules than pets. Allegiant’s public guidance says it accepts trained service dogs that meet federal air travel requirements. If you’re flying with a trained service dog, follow the airline’s service animal instructions and be ready to present any required forms.

If your animal is not a trained service dog, treat it as a pet for planning purposes. Airline staff may deny boarding to animals that show aggressive behavior or can’t be safely contained.

Common Snags And How To Avoid Them

Carrier is “within size” but still doesn’t fit

Under-seat spaces vary by aircraft and seat row. A carrier can still be awkward if it has stiff corners or bulky pockets. Soft-sided styles usually slide in easier.

Connecting flights make the fee feel higher

Since the charge is per segment, two short legs can cost more than a single nonstop in total pet fees. If you’re price shopping, compare nonstop vs. connecting itineraries with the pet fee included.

Long lines at security

You’ll remove your pet from the carrier during screening, then send the empty carrier through the X-ray belt. Practice a calm “hold” at home and use a snug harness so you’re not wrestling a squirmy pet in a crowded lane.

Gate-area stress

Airports can be loud. Keep the carrier partially covered with a light cloth so your pet has less visual stimulation. Skip heavy treats right before boarding to reduce tummy upset.

Pre-Flight Checklist For A Smooth Allegiant Pet Trip

When	What To Do	Why It Helps
7–10 days out	Measure your carrier and confirm it fully closes	Stops last-minute carrier swaps
7–10 days out	Add the pet to the reservation and review fees per segment	Avoids sold-out pet spots
3–5 days out	Carrier practice: short rides, calm rewards, door closed	Reduces crying and pawing during the flight
1–2 days out	Prep pads, wipes, a small trash bag, and a collapsible bowl	Keeps cleanup simple if there’s a mess
Travel day	Use a pet relief area before check-in and again before boarding	Makes the under-seat ride easier for your pet
Security	Clip leash and harness, then carry your pet through the metal detector	Prevents escape while the carrier is screened
On board	Slide the carrier under the seat, keep it level, and don’t open it	Helps your pet stay settled
After landing	Wait for a clear aisle, then exit and head to the nearest relief area	Avoids a stressed pet in a packed jet bridge

Packing Smart When The Carrier Counts As Your Carry-On

Once the pet carrier takes up one of your allowed items, keep the rest of your stuff tight: ID, meds, a charger, and a small pet kit with pads and wipes.

When Allegiant Is Not The Right Choice

If your pet is large or can’t stay settled in an under-seat carrier, this setup can be a bad match. A different airline or a non-flight plan may fit better.

If you’re traveling with more than one animal, plan the carrier count and add each pet early, since pet spots can sell out.

Reality Checks Before You Click “Buy”

Run through these checks before you pay:

• Your carrier fits Allegiant’s published maximum for soft or hard styles.
• Your seat choice has under-seat space in front of you.
• You counted segments, not just travel days, when budgeting the pet fee.
• Your pet can stay calm in a closed carrier for the full airport-to-airport window.
• You’ve checked any local animal entry rules for your destination.

If those boxes are checked, Allegiant’s pet option is usually straightforward. Most problems happen when the carrier is a hair too big, the pet wasn’t acclimated to being closed in, or the traveler waited to add the pet until arrival at the airport.