The former child star, who shot to fame in 1990 as the child star of blockbuster movie Home Alone, made a rare public appearance to attend the annual awards show where he handed over the Favourite Male Artist Award to Post Malone.
Viewers who were shocked to see the 38-year-old after years out of the spotlight took to Twitter to express their delight.
One wrote: “It was so good to see Macaulay Culkin on the AMA’s American Music Awards!!!! He looked great!!!”