"Atago" saw combat service in the First Sino-Japanese War of 1894-1895 under the command of Lieutenant Commander Inoue Yoshitomo, patrolling between Korea, Dairen and escorting Japanese transports. During the Battle of Weihaiwei, "Atago" covered Japanese landing operations on 18 January 1895 (along with and ) and shelled Chinese forts on 29 January and 7 February. On the night of 5 February, "Atago" participated in a night operation with , in which the gunboats made a feint attack on the north entrance to the harbor as a diversion while torpedo boats attacked from the east entrance, sinking the Chinese battleship and damaging the cruiser . After the surrender of China, "Atago" and "Chōkai" remained at Weihaihei as part of the Japanese occupation force.