On this page (5 sections)
The route in one look
Heathrow Terminal 5 to Edinburgh, with one airport at the far end.
The route runs from Heathrow (LHR) to Edinburgh (EDI), and it serves both readings: someone searching Edinburgh to Heathrow wants the same facts. Edinburgh has a single airport, so unlike Glasgow or Belfast there is nothing to disambiguate at the Scottish end.
Edinburgh Airport gives the flight time as 1h 35m, across a straight-line distance of about 332 miles, or 534 km. Departures use Terminal 5, which is the detail that matters most on this route, and not only for finding the check-in desk.
Gate to gate, an hour and a half is fast. Door to door it is a different story, and being honest about that is the point of this page: Heathrow is a large airport with a long walk and a security queue, and Edinburgh Airport sits eight miles west of the city with a tram ride still to come. Count all of it before you decide this is the quick option.
Who flies it
British Airways alone from Heathrow, with the competition at other London airports.
British Airways is the only airline flying Heathrow to Edinburgh non-stop. That is a function of Heathrow rather than of the city pair: Edinburgh is well served from London overall, but the low-cost carriers fly it from Gatwick, Luton and Stansted rather than from here. If British Airways does not work for your dates, the realistic alternative is a different London airport, not a different airline at this one.
The single-carrier position cuts both ways. There is no fare competition on the route at Heathrow, but British Airways operates it as a core domestic service with a serious frequency, and it is integrated with the airline's network in a way a standalone low-cost flight is not. The airline line-up at Heathrow shows where it sits, and every direct route from Heathrow puts the domestic services alongside the long-haul map.
Departure times shift with the season, so use the airline's timetable to book and the live departures board for the day itself.
Flying or the train
On this route the train genuinely competes, and often wins.
This is the domestic route where an airport guide has to be straight with you: for a lot of trips, the train is better. LNER runs 29 direct trains a weekday from London King's Cross to Edinburgh, and the fastest take about 4h 08m. That is city centre to city centre, with no bag drop, no security queue and no onward transport at the far end.
Set that against the flight. An hour and a half in the air becomes something closer to four and a half hours door to door once you add getting to Heathrow, the recommended check-in window, the walk through Terminal 5, and the tram from Edinburgh Airport into the city. For a traveller starting in central or north London and finishing in central Edinburgh, the two are close, and the train is far less likely to go wrong.
Flying wins when the geography or the trip shape changes. If you are starting west of London, near Heathrow already, the airport is the convenient end of town and King's Cross is an hour away before you begin. If your destination is outside central Edinburgh, the airport may be closer than Waverley. And if you are connecting, which is the next section, rail is not a substitute at all.
At Terminal 5
The terminal that makes this route worth flying: connections.
Edinburgh services depart from Terminal 5, and that is the single strongest argument for this flight. T5 is British Airways' main long-haul base at Heathrow, so an Edinburgh leg feeding a long-haul departure is usually a same-terminal connection: your bags are checked through from Edinburgh, you stay airside, and you do not re-clear security into another building. Our Terminal 5 guide covers the layout, and the terminal map shows how the main building and the satellites connect.
This is the traffic the route is really built for. Someone flying Edinburgh to Heathrow to catch a flight to Singapore is not choosing between the plane and the train, because the train does not connect to anything: arriving at King's Cross with a suitcase and a long-haul departure from T5 that evening is a worse trip in every respect. For those passengers the domestic leg is part of one ticket, with one baggage tag and one airline responsible if it runs late. Our guide to connecting at Heathrow covers minimum connection times and what happens when the first leg slips.
For the domestic trip itself, T5 is straightforward: security is the usual constraint on how early to arrive, and the Terminal 5 lounges are available to eligible passengers. There is no immigration control on a domestic flight in either direction, though you do need photo identification the airline accepts.
Who it suits
A connecting passenger's route first, and a point-to-point traveller's second.
Fly this route if you are connecting. If the Edinburgh leg is feeding a long-haul departure from Terminal 5, it is the right choice by a wide margin, and the through-ticket protection, the checked-through bags and the same-terminal transfer are worth more than any time saving. That is the case the route is designed around and the one where nothing else comes close.
Fly it if the geography suits: starting near Heathrow, or finishing outside central Edinburgh, both shift the balance decisively toward the plane.
Otherwise, look hard at the train first. For a central-London-to-central-Edinburgh trip with no onward flight, LNER from King's Cross is competitive on time, better on reliability and simpler in every practical respect, and an airport guide that told you otherwise would not be much use. The route that inverts this logic is Glasgow to Heathrow, where the inbound connecting case is even stronger.