The song of the year was Little Big Town's "Better Man," which Swift wrote for the four-member group. Swift was the sole writer of the song and was granted the award.
Swift wasn't in attendance at the CMA Awards show in Nashville, but Little Big Town's Karen Fairchild accepted the award on her behalf.
"Taylor, wherever you are, thank you for this beautiful song and for loving songs and loving Nashville," Fairchild said.
Little Big Town also won best vocal group of the year.
Brooks, who has been on tour this year with his 2016 album Gunslinger, was presented his entertainer of the year award by country music legend Reba McEntire.
"Getting this presented to me by the entertainer of a lifetime, I thank you," he said, referring to McEntire. "Miranda [Lambert] said it best, Little Big Town said it best -- we're a family. All you guys down here on the front row: We can all agree on one thing. Let's all raise a toast. ... to the band and crew. I was talking to Kelsea [Ballerini] backstage about how we get to do this for a living. ... The most important thing other than God...is you [fans]. ...I love you guys. We're a family."
Other winners include Chris Stapleton, who won best album for From A Room: Volume 1, as well as best male vocalist; Miranda Lambert for best female vocalist; guitarist Mac McAnally for musician of the year; Brothers Osborne for best vocal duo and best video for It Ain't My Fault; and Jon Pardi for best new artist of the year.