Icelandair is offering Roundtrip Flight Tickets from Seattle (SEA) to London (LGW) from $312.

1. Go to Priceline

2. Choose to depart from SEA

3. Choose to go to LGW

4. Depart on SEA
- November 12, 23, 25
- December 2, 7, 9

5. Returns
- November 19, 22, 28, 30
- December 2, 3, 9, 10, 14, 16