It was a two-bay equal-span biplane with a fixed tailskid landing gear, with the wheels supported on skids and powered by a nose-mounted 120 hp (89 kW) Austro-Daimler engine driving a four-bladed propeller.

Some modified single-seat high altitude aircraft were built with extended-span (57 ft 2⅓ in or 17.43 m) upper wings supported by a pair of outward-leaning struts.

[1] Other R.E.5s were used for experimentation with airbrakes and for test flying the Royal Aircraft Factory 4 engine.

[3] Captain John Aidan Liddell was awarded the Victoria Cross for an action on 31 July 1915, being badly wounded when flying an R.E.5 but successfully recovering the aircraft and saving his observer.

[2] One of the aircraft with extended upper wings set a new world altitude record of 18,900 ft (5,760 m) on 14 May 1914, piloted by Norman Spratt.