Hosted by comedian Jeff Foxworthy, the program airs live April 10 from Nashville.
"I've been around a long time, and life still has a whole lot of surprises for me," said the 56-year-old Williams, who joins such previous winners as Loretta Lynn, Reba McEntire and the Dixie Chicks.
CMT said Williams' creativity and passion have helped shape country music.
Williams, the son of Hank Williams Sr., began his career performing his legendary father's songs but in the 1970s forged his own musical identity by fusing country music with the Southern rock of groups such as the Allman Brothers, Lynyrd Skynyrd and the Marshall Tucker Band.
"My manager back then said I was nuts. He said, `I don't know what's wrong with you. Just do your daddy's stuff,'" Williams recalled during a recent interview.
When he performed, "if I had, oh, 1,000 people and if 600 of them got up and left, I would tell them where the exit was. Guess what? The 400 that stayed turned into 4,000 and then turned into 40,000."
Williams has sold 50 million albums with hits including "Texas Women," "Born to Boogie," "Family Tradition" and "All My Rowdy Friends (Are Coming Over Tonight)."
He also was a pioneer in music videos, pairing with friend Waylon Jennings in 1983 for his first one, "The Conversation." The following year he called on Jennings, George Jones, Willie Nelson, George Thorogood and others to appear in his "All My Rowdy Friends" video.
He used cutting-edge production in 1989 to create the illusion of him performing a duet with his late father on the video for "There's a Tear in My Beer."
That same year Williams reached a broader audience when he began performing the "Monday Night Football" anthem "Are You Ready for Some Football," a role that has earned him four Emmys.
There have been obstacles along the way, including drug and alcohol abuse and a suicide attempt in 1974. He broke the bones in his face and almost died in a mountain-climbing accident in Montana in 1975. To hide the scars, Williams adopted his trademark look: a beard, cowboy hat and dark sunglasses.
Last year longtime friend-manager Merle Kilgore died, and this month his daughters — Holly Williams, 25, and Hilary Williams, 27 — were seriously injured when their sport utility vehicle flipped several times on a Mississippi highway.
Williams said he never would have envisioned how his life has turned out.
"My spot in this whole thing is in a place I never dreamed it would be," he said. "Let's go back there and say, `What are the odds that this kid would be singing with Kid Rock at the Super Bowl and winning Emmy awards.' I mean, come on. I like to aim high, but I would have taken that bet back then."