The Boeing Starliner is a class of partially reusable spacecraft designed to transport crew to the International Space Station (ISS) and other low-Earth-orbit destinations. It is manufactured by Boeing, with the Commercial Crew Program (CCP) of NASA as the anchor customer. The spacecraft consists of a reusable crew capsule and an expendable service module.

A reusable spacecraft is a class of spacecraft that have been designed with repeated launch, orbit, deorbit and atmospheric reentry in mind. This contrasts with conventional spacecraft which are designed to be expended after use. Examples of reusable spacecraft are spaceplanes and space capsules like the SpaceX Dragon. Such spacecraft need mechanisms to prevent the disintegration of the spacecraft and its occupants/cargo during reentry. Failure of such systems may be catastrophic, as what happened in the Space Shuttle Columbia disaster.