Hawker Siddeley was a group of British manufacturing companies engaged in aircraft production. Hawker Siddeley combined the legacies of several British aircraft manufacturers, emerging through a series of mergers and acquisitions as one of only two such major British companies in the 1960s. In 1977, Hawker Siddeley became a founding component of the nationalised British Aerospace (BAe). Hawker Siddeley also operated in other industrial markets, such as locomotive building and diesel engine manufacture. The company was once a constituent of the FTSE 100 Index.

Hawker Aircraft Limited was a British aircraft manufacturer that was responsible for some of the most famous products in British aviation history.