AMT may refer to:

• The ICAO code for ATA Airlines
• Aircraft Maintenance Technician, a term used in the United States
• Aviation Maintenance Technician, a United States Coast Guard rating

a-Methyltryptamine (abbreviated as aMT, AMT) is a psychedelic, stimulant, and entactogen drug of the tryptamine class. It was originally developed as an antidepressant by workers at Upjohn in the 1960s, and was used briefly as an antidepressant in Russia under the trade name Indopan before being discontinued.