Hawker Siddeley Dynamics Limited (HSD) was a defence and electronics manufacturer formed on 1st July 1963 as part of a reorganisation within the Hawker Siddeley Group. The new company was a consolidation of the missile and equipment interests of De Havilland, Whitworth Gloster and A.V. Roe, all of which had previously operated separately within the Group.

The new establishment consisted of over 15,000 staff, headed by Sir Arnold Hall as chairman, operating on sites at Hatfield, Lostock, Farnworth, Lakefield, Stevenage, Welkin House, Conquest House, Woodford, Whitely, Spadeadam and Woomera. It would take over all of the projects these companies were involved in including the Firestreak, Blue Streak, Red Top, Blue Steel, Seaslug and CF.299 missiles, and various air-conditioning, fuel control and power supply projects. It also continued as the British representative on the ELDO (European Launcher Development Organisation) project.

In August 1964 the company was chosen to supply air-conditioning equipment to the Concorde project and also announced the development of the Sea Dart missile for the Royal Navy. In 1966 it would also announce a further missile project when the Martel was unveiled in cooperation with Engins Matra. Beyond these military projects, there was also a great deal of work in the civilian sector including the design of the suspension and brake system for British Rail’s prototype Advanced Passenger Train (APT), which was awarded to them in 1969.

In 1977 the Aircraft and Ship Building Act created British Aerospace (BAe) and Hawker Siddeley Dynamics, along with Hawker Siddeley Aviation, the British Aircraft Corporation and Scottish Aviation, were merged into it. The none aviation aspects of Hawker Siddeley would continue as a separate company until 1991 when it was acquired by BTR.