Heathrow to Sydney: No Direct Flights, No Single Terminal

There are no nonstop flights between London Heathrow (LHR) and Sydney (SYD). The distance (~17,000 km / 10,500 mi) exceeds current commercial aircraft range (Qantas "Project Sunrise" A350-1000ULR aims to change this from late 2025).

Typical Connections

• 1-stop (most common): Singapore (SIN), Dubai (DXB), Doha (DOH), Hong Kong (HKG), Kuala Lumpur (KUL), Bangkok (BKK), Perth (PER).
• 2-stop: Any combination (e.g., LHR-DXB-SIN-SYD).

Terminals at Heathrow

Depends entirely on the airline and connecting carrier:

• Terminal 2 (Queen's Terminal): Star Alliance (Singapore Airlines, Thai, United, Air Canada, Lufthansa, etc.).
• Terminal 3: Oneworld (Qantas, Emirates, Cathay, Qatar, Malaysia, American, etc.) + some others.
• Terminal 4: SkyTeam (Delta, Air France, KLM, Korean, Vietnam, etc.) + some non-alliance.
• Terminal 5: British Airways, Iberia (IAG).

Your terminal for the LHR leg = your departing airline's terminal. Your connecting terminal at the hub depends on that airport's layout.

Check your ticket/itinerary. Allow 2.5–3 hrs for connections at major hubs.