天冬氨酸氨基转移酶（英语：Aspartate Transaminase，缩写 AST），也称作谷草转氨酶(SGOT)，是一种磷酸吡哆醛蛋白质，也可以作用于L-苯丙氨酸、L-酪氨酸和L-色氨酸（EC2.6.1.1）。

Aspartate transaminase (AST) or aspartate aminotransferase, also known as AspAT/ASAT/AAT or serum glutamic oxaloacetic transaminase (SGOT), is a pyridoxal phosphate (PLP)-dependent transaminase enzyme (EC2.6.1.1) that was first described by Arthur Karmen and colleagues in 1954. AST catalyzes the reversible transfer of an α-amino group between aspartate and glutamate and, as such, is an important enzyme in amino acid metabolism. AST is found in the liver, heart, skeletal muscle, kidneys, brain, and red blood cells. Serum AST level, serum ALT (alanine transaminase) level, and their ratio (AST/ALT ratio) are commonly measured clinically as biomarkers for liver health. The tests are part of blood panels.