A captive screw is a type of screw that is designed to remain attached to one of the components it is fastening, even when it is fully removed from the other component. This prevents the screw from becoming separated or lost during maintenance, repair or disassembly procedures.

Captive screws typically have heads that are larger than the holes through which they pass, and may be held in place by a spring, a washer or other means. They are commonly used in electronic equipment, industrial machinery, and other applications where frequent access to internal components is required.