HMS Benbow was the third of four Iron Duke-class battleships of the Royal Navy, the third ship to be named in honour of Admiral John Benbow. Ordered in the 1911 building programme, the ship was laid down at the William Beardmore and Company shipyard in May 1912, was launched in November 1913, and was completed in October 1914, shortly after the outbreak of the First World War. The four Iron Dukes were very similar to the preceding King George V class, with an improved secondary battery. She was armed with a main battery of ten 13.5-inch (343 mm) guns and twelve 6 in (152 mm) secondary guns. The ship was capable of a top speed of 21.25 knots, and had a 12-inch (305 mm) thick armoured belt.

The Iron Duke class was a group of four dreadnought battleships built for the British Royal Navy before the First World War. The class comprised four ships: Iron Duke, Marlborough, Benbow, and Emperor of India. Launched from October 1912 to November 1913, this was the third class of Royal Navy super-dreadnoughts. The ships were essentially repeats of the King George V-class battleships; they retained the same ten 13.5 inch (34.3 cm) guns in five twin gun turrets on the centreline. However, the Iron Dukes had improved armour and a more powerful secondary armament of 6-inch weapons instead of the 4-inch mounted on the earlier ships.