A. major may refer to:

• Ademosyne major, an extinct beetle species in the genus Ademosyne, the family Ademosynidae and the superorder Archostemata
• Allactaga major, the great jerboa, a rodent species found in Kazakhstan, Russia, Turkmenistan and Uzbekistan
• Amphicyon major, an extinct carnivorous mammal species from the middle Oligocene and early Miocene found in 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

See also

• Major (disambiguation)
• A major, a note