Heathrow (LHR) has the broadest public-transport choice of the London airports, with three direct rail/Tube options into central London plus coaches, buses, taxis and road access.
Rail and Tube
Three direct public-transport options reach central London. The Heathrow Express runs non-stop to Paddington; the Elizabeth line serves Paddington and continues across central London; the Piccadilly line is slower but usually cheaper and serves central London directly. Oyster/contactless works on the Elizabeth and Piccadilly lines. Check TfL Go for London services and National Rail for wider rail connections.
Coach, bus and road
National Express and other coach operators connect Heathrow with central London, other London airports and cities around the UK. Heathrow also has local buses, taxis, private hire and direct access to the M4/M25. The airport's official transport planner is the best live starting point.
Typical central-London choices
Use Heathrow Express when Paddington and speed matter most; the Elizabeth line for a broader set of central-London destinations; and the Piccadilly line when price matters more than journey time. For airport changes, see Airport-to-airport transfers.