"I just wanted to make a mention of the fact that this award and everysingle award given out tonight were voted on by the people", the singer said.
She also picked up three other awards, for best female pop artist, best tour, and best pop album for "reputation", the biggest seller of 2017.
'Young people of America, the biggest election of our lifetime is happening on November 6. Additionally, several of gospel and R&B's heaviest hitters will assemble for what's sure to be a touching Aretha Franklin tribute.
Swift used her acceptance speech for artist of the year to encourage her fans to vote.
"This award and every single award given out tonight are voted on by the people, and you know what else is voted on by the people?"
The Billy on the Street star was referring to Swift's usually political post to endorse two Democratic Tennessee Congressional candidates; Senate candidate Phil Bredesen and House of Representatives candidate Jim Cooper for the November midterm elections.
Broward County rapper XXXTentacion - who was fatally shot during a June robbery - was honored Tuesday at the American Music Awards in Los Angeles.
Swift is nominated for the top prize - artist of the year - where she will compete with Ed Sheeran, Imagine Dragons, Post Malone and Drake, who ties with Cardi B for most nominations with eight.
This year's AMAs are once again hosted by Tracee Ellis Ross, star of ABC's sitcom Black-ish. As of now, the show has yet to announce whether she won a 23rd in the favourite female artist - pop/rock category. "I'm so nervous, " Bernard said as the audience cheered her on. Other performers include Cardi B with Bad Bunny and J Balvin, Mariah Carey, Carrie Underwood, twenty one pilots and Jennifer Lopez.