A. major

A. major may refer to:
 * Ademosyne major, an extinct beetle species in the genus Ademosyne, the family Ademosynidae and the suborder Archostemata
 * Allactaga major, the great jerboa, a rodent species found in Kazakhstan, Russia, Turkmenistan and Uzbekistan
 * Ammosaurus major, an extinct herbivorous dinosaur from the Early Jurassic of New England, probably synonymous with Anchisaurus polyzelus
 * Amphicyon major, an extinct carnivorous mammal species from the middle Miocene found across Europe and in western Turkey
 * Aphrastochthonius major, a pseudoscorpion species in the genus Aphrastochthonius and the family Chthoniidae
 * Arachis major, a flowering plant species in the genus Arachis native to South America