Campbell was best known for his 1975 hit, "Rhinestone Cowboy," but released more than 70 albums throughout his 50-year career. He won four GRAMMYs in the country and pop categories in 1976, and won CMA's Entertainer of the Year award in 1968.
Outside of the music world, Campbell will be remembered as an actor and TV host, as he starred in his own variety show, The Glen Campbell Goodtime Hour, on CBS from 1969-1972. He also starred in the 2014 documentary, I'll Be Me, which documented his farewell tour and struggle with Alzheimer's disease.
Campbell is survived by his wife, Kim, and eight children.
"Heartbroken. I owe him everything I am, and everything I ever will be," his daughter, Ashley, wrote on Twitter. "He will be remembered so well and with so much love."
In lieu of flowers, the family is asking that donations be made to the Glen Campbell Memorial Fund at BrightFocus Foundation through the CareLiving.org donation page.
ET caught up with Kim in 2015, where she gushed about her husband's 2015 GRAMMY nomination for "I'm Not Gonna Miss You" (he won the award shortly after), and opened up about his battle with Alzheimer's.
"He still knows who I am and we kiss and cuddle," she said. "And I know he knows who I am because of the way he kisses me. We still love each other very much."