The 41-year-old man suffered fatal injuries on the A259 De La Warr Road, in Bexhill, East Sussex, at 7am yesterday after the collision with the lorry, which was travelling in the same direction, Sussex Police said.
The cyclist was taken to hospital but later died, a force spokeswoman added.
A 60-year-old man from Leeds was arrested in Eastbourne a short time after the crash on suspicion of failing to stop and remains in police custody. The spokeswoman said part of the A259 was closed until 11am while police officers investigated the scene.
Sgt Paul Skinner said: “We are still investigating the circumstances surrounding the incident and would like to hear from anyone who may have witnessed the collision.”