The Pillau class of light cruisers was a pair of ships built in Germany just before the start of World War I.

After the outbreak of World War I, however, the German Kaiserliche Marine (Imperial Navy) confiscated the ships before they were completed.

Pillau participated in the Battle of the Gulf of Riga in August 1915, and Elbing took part in the bombardment of Yarmouth and Lowestoft in April 1916.

Elbing was accidentally rammed and immobilized by the German battleship SMS Posen in the confused night fighting, and her crew were ultimately forced to scuttle her.

She served in the Regia Marina (Royal Navy) until June 1943, when she was sunk in Livorno by USAAF bombers, and eventually broken up for scrap in 1948.

In 1912, the Russian Navy sought builders for a pair of light cruisers; the Schichau-Werke shipyard in Danzig won the contract.

The two ships were originally ordered by the Russian Navy as Maraviev Amurskyy and Admiral Nevelskoy from the Schichau-Werke that year.

The standard 10.5 cm (4.1 in) SK L/45 gun used on previous German cruisers was considered, but abandoned in favor of a larger weapon.

Sloping armor 40 mm (1.6 in) thick provided a measure of protection on the upper portion of the ships' sides.

[3] Pillau spent the majority of her career in II Scouting Group, and saw service in both the Baltic and North Seas.

She assisted the badly damaged battlecruiser SMS Seydlitz reach port on 2 June after the conclusion of the battle.

[10] In the early years of World War II, she provided gunfire support to Italian troops in several engagements in the Mediterranean.

[11] In 1943, she was slated to become an anti-aircraft defense ship, but while awaiting conversion, she was sunk by USAAF bombers in Livorno in June 1943.

She was heavily engaged in the confused fighting on the night of 31 May – 1 June, and shortly after midnight she was accidentally rammed by the battleship Posen, which tore a hole in the ship's hull.