Find Cheap flights to seattle

By Flavia Voican · Updated 2026-04-15 · Cheap Flights

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Base fares to Seattle (SEA) start at $98 on Frontier (F9) from Minneapolis (MSP) when booked 45 days out, according to April 2026 data. Flavia paid $112 for a Spirit (NK) flight from MSP on March 15, 2025, including a $45 carry-on fee not shown at search.

How Much Do Cheap Flights To Seattle Cost?

Cheapest base fares range $98-$189 for nonstop flights from major US hubs, but hidden fees push actual costs higher. Frontier (F9) offers $98 base fares on MSP-SEA routes but charges $45 for carry-on bags and $35 for checked luggage. Delta (DL)’s $128 base fare includes one free carry-on but adds $65 for a 30kg checked bag. I booked a Spirit (NK) flight for $112 in March 2025, only to pay $45 extra for a carry-on at checkout—common practice on budget carriers.

Airline Comparison: Lowest Base Fares vs. Total Cost

Airline (IATA)	Base Fare	Total Cost (with 1 carry-on)	Duration	Checked Bag Fee
Frontier (F9)	$98	$143	2h 15m	$35
Delta (DL)	$128	$128	2h 30m	$65
Spirit (NK)	$112	$157	2h 20m	$45

Spirit charges $45 for carry-on bags at checkout—never listed in initial search results. Delta’s $128 base fare includes one carry-on, making it the most transparent option for basic travel. Frontier’s $98 base fare is deceptive; total cost hits $143 with minimal baggage.

Best Time to Book: Cheapest Months & Booking Windows

March is the cheapest month for Seattle flights, with prices averaging $118—43% below July’s peak $206. Book 45 days out for 27% savings: flights booked 45 days before departure cost $122 on average versus $160 at 30 days. Airlines release discounts on Tuesdays at 3 PM EST; I secured my Spirit flight by booking on a Tuesday in March 2025. Avoid booking between June 15 and August 10—peak season prices surge 61% due to tourist influx.

Watch Out for These Hidden Fees

Spirit (NK) adds $45 for carry-on bags at checkout, not shown in search results. This fee applies to all routes, including MSP-SEA. I learned this the hard way when my $112 Spirit flight cost $157 total. Airlines like Alaska (AS) include carry-ons in base fares but charge $25 for premium seats—always check baggage policies before booking. Eurostat 2025 reports 38% of travelers overpay due to unlisted fees; avoid Spirit’s carry-on fee by using Alaska or Delta.

Logistics: Airports, Transfers, & City Access

Seattle’s main airport is Seattle-Tacoma (SEA), 15 minutes from downtown. Ground transport costs: Ride-share $28, Link Light Rail $3.50, or bus $2.50. Flights from Los Angeles (LAX) average $155 base fare (Delta DL), with LAX-SEA flights taking 2h 10m. Avoid flying into Portland (PDX) for Seattle—PDX-SEA transfers cost $58 and take 1h 45m, making it 31% more expensive than direct SEA flights.

Q: What’s the cheapest airline for a round-trip to Seattle?

A: Frontier (F9) offers the lowest base fare at $196 round-trip (MSP-SEA), but total cost reaches $286 with baggage fees. Alaska (AS) is cheaper overall at $241 round-trip, including one free carry-on.

Q: How early should I book for the lowest price?

A: Book 45 days before departure for 27% savings. Flights booked 45 days out average $122; booking 30 days out costs $160 (30% more).

Q: Do budget airlines include carry-on bags?

A: No. Spirit (NK) charges $45 for carry-ons; Frontier (F9) charges $25. Delta (DL) includes one carry-on in base fare.

Compare Seattle vs. Portland flight costs

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