Terminal 2  [map]
      Aegean Airlines, A3
      Aer Lingus Airlines, EI
      Air Canada Airlines, AC
      Air China Airlines, CA
      Air India Airlines, AI
      Air New Zealand Airlines, NZ
      ANA Airlines, NH
      Asiana Airlines, OZ
      Austrian Airlines, OS
      Brussels Airlines, SN
      Croatia Airlines, OU
      Egyptair Airlines, MS
      Ethiopian Airlines, ET
      Eurowings Airlines, EW
      EVA Air Airlines, BR
      FlyBE Airlines, BE
      Icelandair Airlines, FI
      LOT Polish Airlines, LO
      Lufthansa Airlines, LH
      SAS Scandinavian Airlines , SK
      Singapore Airlines, SQ
      South African Airways Airlines, SA
      Swiss International Air Line , LX
      TAP Air Portugal Airlines, TP
      Thai Airways International Airlines, TG
      Turkish Airlines, TK
      United Airlines, UA
Terminal 3  [map]
      American Airlines, AA
      British Airways Airlines, BA
      Cathay Pacific Airways Airlines, CX
      Delta Airlines, DL
      Emirates Airlines, EK
      Finnair Airlines, AY
      Garuda Indoesia Airlines, GA
      Iran Air, IR
      Japan Airlines (JAL), JL
      LATAM, LA
      Middle East Airlines, ME
      Pakistan International Airlines, PK
      Philippine Airlines, PR
      Qantas Airways Airlines, QF
      Royal Jordanian Airlines, RJ
      Srilankan Airlines, UL
      Virgin Atlantic Airways Airlines, VS
      Vueling Airlines, VY
Terminal 4  [map]
      Aeroflot Russian Airlines, SU
      Aeromexico Airlines, AM
      Air Algerie Airlines, AH
      Air Astana , KC
      Air France Airlines, AF
      Air Malta Airlines, KM
      Air Mauritius Airlines, MK
      Air Serbia, ASL
      Alitalia Airlines, AZ
      Arik Air, W3
      Avianca Airlines, AV
      Azerbaijan Hava Yollary Airlines, J2
      Biman Bangladesh Airlines, BG
      Bulgaria Air Airlines, FB
      China Eastern Airlines, MU
      China Southern Airlines, CZ
      El Al Airlines, LY
      Etihad Airlines, EY
      Gulf Air Airlines, GF
      Jet Airways Airlines, QJ
      Kenya Airways, KQ
      KLM Airlines, KL
      Korean Air Lines Airlines, KE
      Kuwait Airways, KU
      Malaysia Airline Airlines, MH
      Oman Air, WY
      Qatar Airways Airlines, QR
      Royal Air Maroc Airlines, AT
      Royal Brunei Airlines, BI
      Saudia Airlines, SV
      TAROM Romanian Air Transport , RO
      Tunis Air Airlines, TU
      Turkmenistan Airlines, T5
      Uzbekistan Airways, HY
      Vietnam Airlines, VN
Terminal 5  [map]
      British Airways Airlines, BA
      Iberia Airlines, IB

More details on airlines from the London Heathrow Airport website.

London Heathrow LHR Terminal map.

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