Wire wrap is an electronic component assembly technique that was invented to wire telephone crossbar switches, and later adapted to construct electronic circuit boards. Electronic components mounted on an insulating board are interconnected by lengths of insulated wire run between their terminals, with the connections made by wrapping several turns of uninsulated sections of the wire around a component lead or a socket pin.

Wires can be wrapped by hand or by machine, and can be hand-modified afterwards. It was popular for large-scale manufacturing in the 1960s and early 1970s, and continues today to be used for short runs and prototypes. The method eliminates the design and fabrication of a printed circuit board. Wire wrapping is unusual among other prototyping technologies since it allows for complex assemblies to be produced by automated equipment, but then easily repaired or modified by hand.

Wire wrap was used for assembly of high frequency prototypes and small production runs, including gigahertz microwave circuits and supercomputers. It is unique among automated prototyping techniques in that wire lengths can be exactly controlled, and twisted pairs or magnetically shielded twisted quads can be routed together.

Wire wrap construction became popular around 1960 in circuit board manufacturing, and use has now sharply declined. Surface-mount technology has made the technique comparatively much less useful than in previous decades. Solder-less breadboards and the decreasing cost of professionally made PCBs have nearly eliminated this technology.

Manually wrapped wires were common in early 20th century point-to-point electronic construction methods in which a strong connection was needed to hold the components in place. Wires were wrapped by hand around binding posts or spade lugs and then soldered.

Modern wire wrapping technology was developed after WWII at Bell Laboratories as a means of making electrical connections in a new relay being designed for use in the Bell Telephone system. A design team headed by Arthur C. Keller developed the "Keller Wrap Gun", and the entire wrap system was passed over to Western Electric for industrial application. After a "make or buy" committee at Western Electric decided to have the hand tool manufactured by an outside vendor, Western Electric sent the tool contract out for bids. Keller Tool of Grand Haven, Michigan, a supplier of rotary hand tools to Western Electric, won the contract and made several design changes to make the tool easier to manufacture and to use. Keller began manufacturing the tools in 1953, and subsequently obtained a license from Western Electric allowing sale of the technology on the open market. The tool was marketed under its original name – since the name of the manufacturer was coincidentally the same as the name of the inventor.

IBM's first transistorized computers, introduced within the late 1950s, were built with the IBM Standard Modular System that used wire-wrapped backplanes.

Wire-wrap was used by Apple Computer to make early prototypes of the original Macintosh computer (The Macintosh 128K).