Icelandair and Aer Lingus has round-trip flights from Newark/New York (EWR/JFK) to London or Rome (LGW/LHR, FCO) for $335-$425 with a connection.
London: Flights January to March on Icelandair. Starting at $335, round-trip.
Rome: Flights February, March, April, May, August, and November on Aer Lingus. Starting at $383, round-trip.
Some small OTAs on Skyscanner have this for cheaper than the airline.
Norse Atlantic UK has round-trip flights from New York (JFK) to London (LGW) for $338-$351, NONSTOP. Flights January to February. Departures on Monday, Tuesday, and Wednesday. Origin/Destination reversible.
Alaska Airlines and British Airways have round-trip flights from Portland (PDX) to London (LHR) for $452-$521, NONSTOP. Flights January to April. 7-day minimum stay required.
Flight is marketed by Alaska Airlines, but operated by British Airways as a code-share.
Norse Atlantic UK has round-trip flights from New York (JFK) to London (LGW) for $332-$346, NONSTOP. Flights in November, January, February, and March. Origin/Destination reversible. No Thanksgiving dates.
British Airways, Finnair, Iberia, Alaska Airlines and various other airlines have round-trip flights from Portland (PDX) to London (LHR) for $545, NONSTOP. Flights October to March. Departures on Monday, Tuesday, and Wednesday. 7-day minimum stay required.
Norse Atlantic UK has round-trip flights from Los Angeles (LAX) to London (LGW) for $379-$437, NONSTOP. Flights September to October. Origin/Destination reversible.
Norse Atlantic is a budget carrier. Fares now allow for a free carry-on bag (22 x 18 x 10 inch less than 22-lbs).
American Airlines, British Airways, and Iberia have round-trip flights from Phoenix (PHX) to London (LHR) for $517, NONSTOP. Flights August to March. Departures on Monday, Tuesday, Wednesday, and Sunday. 7-day minimum stay required.
Flights with stops are available for a bit cheaper; $485, but I don’t think the price difference is worth the stop.
Oneworld has round-trip flights from Portland (PDX) to London (LHR) for $545, NONSTOP. Flights September to March. Departures on Monday, Tuesday, Wednesday, and Sunday. 7-day minimum stay required.
Norse Atlantic UK has round-trip flights from New York (JFK) to London (LGW) for $367-$394, NONSTOP. Flights September to January. Extended weekends available.
British Airways, American Airlines, and Delta have round-trip flights from Seattle (SEA) to London (LHR) for $506-$513, NONSTOP. Flights August to March. Departures on Monday, Tuesday, Wednesday, and Sunday. 7-day minimum stay required.
Nonstop round-trip fares rarely lower than this.
Allows one carry-on bag and one personal item for free. You can avoid paying for seat selection by accepting the randomly assigned seat at the gate.
Oneworld has round-trip flights from Los Angeles (LAX) to London (LHR) for $516, NONSTOP. Flights August to December. Departures on Monday, Tuesday, Wednesday, and Sunday. 7-day minimum stay required. No Christmas dates available.
British Airways, Finnair, Aer Lingus, Iberia and various other airlines have round-trip flights from Denver (DEN) to London (LHR) for $516, NONSTOP. Flights August to December. Departures on Monday, Tuesday, Wednesday, and Sunday. 7-day minimum stay required. No Christmas dates available.
Oneworld has round-trip flights from Portland (PDX) to London (LHR) for $546, NONSTOP. Flights August to March. Departures on Monday, Tuesday, Wednesday, and Sunday. 7-day minimum stay required.
British Airways and Iberia have round-trip flights from Atlanta (ATL) to London, United Kingdom (LHR) for $520-$534, NONSTOP. Flights in August. Departures on Monday, Tuesday, Wednesday, and Sunday. 7-day minimum stay required.
Oneworld has round-trip flights from Chicago (ORD) to London, United Kingdom (LHR) for $527, NONSTOP. Flights in August. Departures on Monday, Tuesday, Wednesday, and Sunday. 7-day minimum stay required.
British Airways and Iberia have round-trip flights from Seattle (SEA) to London, United Kingdom (LHR) for $520, NONSTOP. Flights in August. Departures on Tuesday, Wednesday, and Sunday. 7-day minimum stay required. Limited date selection.
American Airlines, British Airways, and Iberia have round-trip flights from Phoenix (PHX) to London (LHR) for $520, NONSTOP. Flights in August. Departures on Monday, Tuesday, Wednesday, and Sunday. 7-day minimum stay required.
Scandinavian Airlines has round-trip flights from Atlanta (ATL) to London, United Kingdom (LHR) for $426-$446 with a connection. Flights October to March. Extended weekends available.
Norse Atlantic UK has round-trip flights from New York (JFK) to London, United Kingdom (LGW) for $363-$377, NONSTOP. Flights September to November. Extended weekends available. Origin/Destination reversible. No Thanksgiving dates.
Norse Atlantic is a budget carrier. Fares now allow for a free carry-on bag (22 x 18 x 10 inch less than 22-lbs). As well as a very small small personal item (15.5 x 11.5 x 5.5 inch) without additional fees.
Norse Atlantic UK has round-trip flights from Los Angeles (LAX) to London, United Kingdom (LGW) for $343-$399, NONSTOP. Flights August to October. No Tuesday departures. Extended weekends available. Origin/Destination reversible.
Norse Atlantic is a budget carrier. Fares now allow for a free carry-on (bag 22 x 18 x 10 inch less than 22-lbs). As well as a very small small personal item (15.5 x 11.5 x 5.5 inch) is allowed without additional fee. You can avoid paying for seat selection if you accept the randomly assigned seat prior to boarding. Checked and carry-on bags cost between $45 and $70 each-way, depending on weight and size.
