H49

H49 may refer to :
 * HMCS Margaree (H49), a Royal Canadian Navy D-class destroyer
 * HMS Diana (H49), a Royal Navy D-class destroyer
 * HMS H49, a Royal Navy H-class submarine
 * HMS Inconstant (H49), a Royal Navy I-class destroyer
 * Lioré et Olivier LeO H-49, a French flying boat
 * Nelson H-49, an aircraft engine
 * Paralytic strabismus