Diamond plate, also known as checker plate, tread plate and Durbar floor plate, is a type of metal stock with a regular pattern of raised diamonds or lines on one side, with the reverse side being featureless. Diamond plate is usually steel, stainless steel or aluminum. Steel types are normally made by hot rolling, although modern manufacturers also make a raised and pressed diamond design.

The added texture reduces the risk of slipping, making diamond plate a solution for stairs, catwalks, walkways, and ramps in industrial settings. Its non-skid properties mean that diamond plate is frequently used on the interior of ambulances and on the footplates of firetrucks. Additional applications include truck beds and trailer floors.

Diamond plate can also be used decoratively, particularly highly polished aluminum variants. Manufactured in plastic, diamond plate is marketed as an interlocking tile system to be installed on garage floors, trailers, and exercise rooms.

Diamond plate may be used for surface protection against damage from foot traffic or harmful chemicals. Manufactured with polymer variants, inter-locking diamond plate tile is used in areas with high surface-erosive traffic.