For travelers in 2026, the Heathrow Express provides a highly reliable early-morning start for those catching "red-eye" departures or early business flights. From London Paddington, the first train to Heathrow typically departs at 04:34 AM Monday through Saturday, with the first Sunday service starting slightly later around 05:10 AM. If you are traveling from the airport into Central London, the first train from Heathrow Terminal 5 departs at 05:12 AM, reaching the Central station (Terminals 2 & 3) at 05:17 AM before arriving at Paddington at 05:33 AM. Trains run every 15 minutes throughout the day, ensuring a 15-minute transit time to the central terminals. In 2026, while the Elizabeth Line and Piccadilly Line offer cheaper alternatives, the "Express" remains the gold standard for speed, particularly during these early hours when other transit frequencies are lower.