HMS Ajax was the name ship of her class of ironclad battleships built for the Royal Navy during the 1870s.

These were built by John Penn and Sons and each drove a single propeller using steam provided by 10 cylindrical boilers.

The ships carried a maximum of 970 long tons (986 t) of coal, enough to steam 2,100 nautical miles (3,900 km; 2,400 mi) at 9 knots (17 km/h; 10 mph).

[5] To attack the unarmoured portion of their opponents, the Ajax class was fitted with a pair of rifled breech-loading BL 6-inch (152 mm), 80-pounder guns.

[1] Ajax was not commissioned until 30 April 1885 and was assigned to the Particular Service Squadron commanded by Admiral Geoffrey Hornby.

[12] That summer, the squadron evaluated the weapons and defences of a fortified harbour, Berehaven (now Castletownbere), Ireland, against torpedo boats and other threats.

[15] The ship participated in the annual manoeuvres in August 1889 and a shell exploded in one of her 12.5-inch gun barrels on 2 September, wounding one man.

She was further reduced to Dockyard Reserve in November 1901, and was sold to Castles for scrap in March 1904[14] and subsequently broken up at Charlton.