Dan Duvall was a Human Starfleet lieutenant who was assigned as a shuttlecraft pilot for the Vulcan ambassador in the early 2370s.

Prior to 2372, Duvall and Sean Hawk attended the advanced flight training school on Jupiter Station together and became friendly rivals. Over the intervening years, Duvall and Hawk would remain in intermittent contact with each other, and would often tease each other about their current assignments.

In 2372, Hawk contacted Duvall on Vulcan and asked him to investigate and locate Linda Addison's body on Vulcan's Forge after it became clear that she had been killed and replaced by a Changeling infiltrator. Eventually her skeletal remains were found and Duvall contacted Hawk aboard the USS Enterprise-E to inform him. (TNG - Slings and Arrows eBook: A Sea of Troubles)