All of the way forward and aft on the OLYMPIA are the two turrets, each housing two eight inch guns. The present turrets and guns are recreations, the originals having been removed about 1910.

The eight inch guns were the OLYMPIA's most formidable armament, though not truly its best armament. The vessel's five inch guns were responsible for inflicting more damage on the Spanish fleet. The turrets were steam-operated, and therefore did not turn smoothely as did the electronically operated turrets on the USS BROOKLYN. The turret rotated in a jerking motion, which made training the guns on a target particularly challenging. When fired, the smoke from the brown powder generally made the viewports out of the turret unusable, and the viewports had to be cleaned after each shot. The eight inch guns did throw a 250 pound projectile which could penetrate 3 1/2" of armor at a range of five miles. The largest guns in the Asiatic squadron at the time of the Battle of Manila Bay were the eight inch guns.