Lynn died at age 71 on Friday, Common said in an interview Monday in Los Angeles. He gave no further details.
Lynn was a star high school basketball player in Chicago and played in the 1969-1970 season in the American Basketball Association. He struggled with drug addiction and with being a father to six children, topics he addressed in poignant, sometimes regretful poems that concluded many of Common's albums.
"He was truly a natural poet and master of words. His personality and soul shined through his work," Common, whose real name is Lonnie Rashid Lynn Jr., said in the interview Monday.
"The way he said things made me look at life and the world in a new way, in a different way. They always sparked a thought in my head. His words would always make me strive to achieve higher, to write better, to be more truthful with my words."
Common is also an actor, appearing in films including "Terminator: Salvation" and "LUV" and as a regular on the AMC series "Hell on Wheels."
Lynn, known as "Pops" on Common's albums, recorded his last poem for the rapper's 2011 release, "The Dreamer/The Believer."
"For those of us who come from less than enviable circumstances, dreams - good dreams, sweet dreams - dreams come true. Truthful dreams, truthful dreams become life," he intoned in the song, called "Pops Belief."
"Live the life you believe. The American dream, the black American dream, the universal dream. For the sake of the unwritten laws of humanity, I believe in God. I believe in my ancestors, I believe in my offsprings ... I believe in the truth, truth. See you next lifetime."