Flights Under $100: How to Find Ultra-Cheap One-Way Deals

Flights under $100 one-way aren’t unicorns. They exist on dozens of routes, every week, if you know where to look. Here’s how to consistently find them.

Routes that regularly go under $100

These aren’t error fares or once-a-year sales. These routes hit sub-$100 one-way pricing on a regular basis.

US domestic (the sweet spot for under $100)

• Chicago → Las Vegas — Frontier and Spirit run this route from $29-49 one-way
• NYC → Fort Lauderdale — Spirit’s bread and butter. $39-59 one-way, multiple daily flights
• Atlanta → New York — Spirit, Frontier, and even Delta dip under $79 on this route
• LA → San Francisco — Southwest runs $49-69 one-way regularly
• Dallas → Denver — Frontier from $29, Spirit from $39
• Las Vegas → LA — One of the cheapest routes in the US. Spirit from $19 in off-peak
• Miami → NYC — JetBlue and Spirit compete hard. $59-89 one-way

International (harder, but possible)

• US → Reykjavik — PLAY runs sales from $99 one-way from East Coast cities
• Within Europe — Ryanair and Wizz Air regularly go under $30 one-way if you’re already on that side of the Atlantic
• US → Mexico City — Volaris and VivaAerobus from border cities (LA, Houston) from $79-99

How to find sub-$100 flights consistently

1. Start with budget carriers

Budget airlines price one-way flights independently — there’s no round-trip penalty. This is the single biggest advantage for one-way deal hunters.

Check these directly:

• Spirit — Best for East Coast and Florida routes
• Frontier — Best for Denver, Vegas, and mid-size city routes
• Southwest — Slightly higher base fares but no change fees, free bags
• Allegiant — Smaller airports only, but crazy cheap ($29-49 fares)

Don’t search these on Google Flights — it doesn’t show all their fares. Use Skyscanner or book direct.

2. Use the “Everywhere” search

Skyscanner’s “Everywhere” feature is the best tool for finding flights under $100 to anywhere. Set your departure airport, pick one-way, set the destination to “Everywhere,” and sort by price. It shows you every available destination ranked from cheapest to most expensive.

This is how you find routes you didn’t know existed. A $39 flight from your city to somewhere unexpected beats a $200 flight to somewhere you planned.

3. Be flexible on dates

A Tuesday or Wednesday departure can be $40 cheaper than a Friday on the same route. Budget carriers especially vary wildly by day.

Use Kayak’s flexible date grid or Google Flights’ price calendar to spot the cheapest day. A one-day shift can mean the difference between $39 and $89.

4. Check nearby airports

Flying from Baltimore instead of DC, Oakland instead of SFO, or Ft. Lauderdale instead of Miami often cuts $30-50 off the fare. Budget carriers love secondary airports because landing fees are lower.

5. Book the right window

For domestic under-$100 fares:

• 1-3 weeks out is the sweet spot
• Same-week can work on budget carriers (unlike legacy airlines that jack up last-minute prices)
• More than 2 months out — budget carrier schedules may not be loaded yet

6. Don’t bother with the Tuesday myth

The “book on Tuesday at 1pm” advice is dead. Airlines use dynamic pricing that changes hundreds of times per day. There’s no magic day or time. What matters is booking when the price is low — and that requires watching fares, not timing your browser refresh.

Error fares: the holy grail of cheap flights

Error fares happen when airlines accidentally publish a wrong price — a $800 flight to Europe showing up for $89. They’re rare, unpredictable, and disappear within hours.

When they hit, they’re almost always one-way fares (round-trip error fares get caught faster). The only way to catch them is through real-time alerts.

We track error fares across all airlines and send instant alerts when we find them. Sign up for under-$100 alerts →

What to watch out for

Hidden fees on budget carriers

That $29 Spirit fare doesn’t include:

• Carry-on bag ($35-65)
• Seat selection ($5-50)
• Any food or drink

Factor in at least one carry-on bag. A $29 fare + $39 bag = $68 total. Still under $100, but not $29.

”From $XX” pricing

Airlines advertise their lowest possible fare, which is usually one specific date, one specific route, basic economy, no bags. The real price for your dates will be higher. Check the actual dates you need.

Refund policies

Most sub-$100 fares are non-refundable basic economy. Southwest is the exception — all their fares are changeable with no fee. If your plans might shift, the slightly higher Southwest fare can be worth it.

Bottom line

One-way flights under $100 are everywhere on domestic routes if you fly budget carriers, stay flexible on dates, and book 1-3 weeks out. For international, sub-$100 is harder but doable on specific routes and during error fares.

We track the best under-$100 one-way deals daily. Browse deals under $100 →