Charles David "Charlie" Walker is an American engineer and astronaut who flew on three Space Shuttle missions in 1984 and 1985 as a Payload Specialist for the McDonnell Douglas Corporation.

A payload specialist (PS) was an individual selected and trained by commercial or research organizations for flights of a specific payload on a NASA Space Shuttle mission. People assigned as payload specialists included individuals selected by the research community, a company or consortium flying a commercial payload aboard the spacecraft, and non-NASA astronauts designated by international partners.