The assistant secretary of defense for space policy (ASD(SP)) is a position in the United States Department of Defense responsible for the overall supervision of DoD policy for space warfighting.

The officeholder reports to the Under Secretary of Defense for Policy.

It was created by the Department of Defense on October 29, 2020 after it was mandated by the National Defense Authorization Act of 2019.

Previously, there was a deputy assistant secretary for space policy position that reports to the Assistant Secretary of Defense for Homeland Defense and Americas' Security Affairs.

Acting Assistant Secretary of Defense for Space Policy Justin T. Johnson was then appointed to perform the duties of the office.