Yakumo was an armored cruiser built for the Imperial Japanese Navy (IJN) in the late 1890s. As Japan lacked the industrial capacity to build such warships herself, the ship was built in Germany. She participated in most of the naval battles of the Russo-Japanese War of 1904–05, and was lightly damaged during the Battle of the Yellow Sea and the Battle of Tsushima. Yakumo saw no combat during World War I and began the first of many training cruises in 1917, although she was not officially reclassified as a training ship until 1931. Her last training cruise was in 1939, but the ship continued to conduct training in home waters throughout the Pacific War. Yakumo became a repatriation transport after the war and was broken up in 1946–47.

The armored cruiser was a type of warship of the late 19th and early 20th centuries. It was designed like other types of cruisers to operate as a long-range, independent warship, capable of defeating any ship apart from a battleship and fast enough to outrun any battleship it encountered.