Hampshire officers were called at 2.05pm to a report that a motorcycle had collided with a tree on Fort Road.
The motorcyclist, a man in his 30s from Gosport, was pronounced dead at the scene.
The man’s next of kin have been informed and police are now looking to speak to any witnesses.
Hampshire officers said: “As part of our investigation, we would like to hear from anyone who was in the area or witnessed the collision, the moments leading up to it or the aftermath.
“Anyone who saw what happened or has any information, including dash cam footage that may assist our enquiries, is asked to call 101 quoting the reference 0884 of March 30th.”
