London City Airport wins for Canary Wharf and Docklands. Stansted wins for northeast London, Hackney and Stratford.
East London is split between two airports. London City Airport is unbeatable for Canary Wharf, Docklands and the Isle of Dogs — the DLR takes ~20 minutes. Stansted is better for northeast London — Hackney, Stratford, Walthamstow — the Stansted Express to Tottenham Hale connects to the Victoria Line. Heathrow and Gatwick are both on the wrong side of London for east London destinations.
Here is how the airports compare for reaching different parts of east London:
London City Airport is purpose-built for east London business travellers. The DLR connects directly from the terminal to Canary Wharf (~20 min), Bank (~25 min) and Stratford (~30 min via Poplar). The total door-to-door journey from landing to office can be under 45 minutes — no other London airport achieves this for Docklands.
Stansted is geographically closer to northeast London than any other airport except City. The Stansted Express serves Tottenham Hale (Victoria Line) and Liverpool Street. From Tottenham Hale, Hackney, Stoke Newington and Walthamstow are a short bus or Overground ride away. For Stratford, the Stansted Express to Liverpool Street then Central Line is the best route.
If London City doesn't serve your route and you are heading to Canary Wharf, Heathrow with the Elizabeth Line (change at Whitechapel for DLR) is the next best option at ~60–75 minutes total. Gatwick is reasonable for southeast London. Luton is rarely the best choice for east London.
London City Airport (LCY) is closest. The DLR takes ~20 minutes from the terminal to Canary Wharf station. This is the fastest airport-to-office connection of any London airport.
Stansted is best for Stratford. The Stansted Express to Tottenham Hale (~40 min), then Victoria Line to Highbury & Islington, then Overground to Stratford (~25 min). Total door-to-door: ~70 minutes. London City Airport via DLR to Stratford (change at Poplar) is also good at ~30–40 minutes.
Heathrow is on the west side of London — a long journey to east London. Elizabeth Line to Whitechapel, then change for DLR or Overground. Total journey to Canary Wharf or Stratford: 60–80 minutes. Only use Heathrow for east London if you have no other choice.
Stansted via Tottenham Hale, then Victoria Line to Highbury & Islington and Overground to Hackney — total ~60–70 minutes. London City Airport via DLR to Stratford then Overground is also good at ~45–55 minutes.