The Nelson-class battleships were the first post-Treaty capital ships to enter service and as a result, incorporated numerous innovations although not all of them proved to be successful. The Nelsons were the most powerful Royal Navy battleships ever built, armed with nine BL 16-in Mk. I guns in three triple turrets. The heavier armament was a concession for the UK in order to have ships that could match the Japanese Nagato-class and US Colorado-class, but in practice the guns proved to be only a modest improvement over the 15-in guns used in previous classes and required frequent servicing. To maintain Treaty limits on displacement, numerous design compromises were taken, notably the positioning of all turrets in the forward deck, thus shortening the superstructure. Secondary armament was also kept aft as a result, on the main deck. Only two shafts were used in order to reduce the size of the machinery and the result was that both ships were considerably slower than their counterparts, just 23 knots, despite a rather efficient hydrodynamic hull design. Armor was sloped to reduced weight and there was consideration given towards protecting the ship from plunging shells and aircraft bombs; there were also air- and water-filled torpedo bulges. Both ships had a successful record during World War II, operating primarily in the Atlantic (where the HMS Rodney participated in the battle against the Bismark) and the Mediterranean mainly as convoy escorts and for coastal bombardment. Both ships provided fire support during the Normandy campaign but were considered too slow for post-war operations and were therefore scrapped.

The HMS Nelson served primarily as a convoy escort and provided fire support for the invasions of North Africa, Sicily, Salerno, and Normandy although it arrived a few days after D-Day. Late in the war it was sent to the Pacific but only saw modest service and was scrapped post-war. The HMS Rodney (along with the HMS King George V participated in the sinking of the Bismark in 1941 hitting it with over a hundred shells. It later joined its sister in the above-mentioned invasions and was one of the three Royal Navy battleships present on D-Day. Having had no refit during its wartime service, it was put in reserve shortly after the Normandy campaign.