W21 (disambiguation)

The W21 was an hydrogen bomb design for the US military.

W21 may also refer to:


 * British NVC community W21, a scrub community in the British National Vegetation Classification system
 * Mercedes-Benz W21, a German sedan
 * Samsung W21 5G, a smartphone
 * Wanderer W21, a German sedan
 * Wilderness 21, an American sailboat
 * The AIATSIS designation for the Tharrkari language
 * The Wenninger index number for a Great dodecahedron