The "Tegetthoff"-class ships were protected at the waterline with an armor belt which measured thick in the central citadel, where the most important parts of the ship were located. This armor belt was located between the midpoints of the fore and aft barbettes, and thinned to further towards the bow and stern, but did not reach either. It was continued to the bow by a small patch of armor. The upper armor belt had a maximum thickness of , but it thinned to from the forward barbette all the way to the bow. The casemate armor was also thick.