"The Green Mile" star died on September 3 in Los Angeles after complications from a heart attack July 13. He was 54.
There were funny stories told and touching memories of Duncan shared during Monday's service. The friends he made in Hollywood during his career came to show their respect and love for the 6-foot-5-inch-tall actor who they looked up to in many ways.
They gathered to say a final farewell to the man who towered over them, gave bear hugs and made a lasting impression.
Duncan was best known for his role in "The Green Mile." He earned an Oscar nomination for Best Actor in a Supporting Role. "Green Mile" director Frank Darabont says Duncan's first audition didn't guarantee him the part, but he won them over during the screen test.
"He started off as the guy who was not going to get the part, and ended up being the only actor in the world who could possibly have played it," said Darabont. "His journey as an artist is one of the most inspired things I've ever been privileged to witness."
Duncan starred in "The Green Mile" with Tom Hanks.
"Michael was in charge of love. He was the guy who just brought a zest and a joy. You always knew when he walked on the set. He always knew when you were involved in a scene with him," said Hanks.
Duncan played the parts of bodyguards, kingpins and was the voice of cartoon characters. Duncan worked as a bodyguard before beginning his acting career in his 30s. In addition to "Green Mile," he also appeared in "Armageddon," "The Scorpion King" and "Sin City."
In July, he suffered a heart attack. His fianc?e, Omarosa Manigault-Stallworth, performed CPR and resuscitated him. But Duncan died last week.
"They told us that he wouldn't make it past three days," said Manigault-Stallworth. "And I just asked them for time, just time so I could find the best doctors, time so I could find the best specialist, time. I just wanted time."
Duncan joined the cast of the TV show "Bones" last season. His honesty and kindness were an inspiration to everyone on set.
"We love Michael Clarke for who he is, what he is, and he is smiling, and he is dancing now. And let's dance with Michael and remember every day he is with us," said "Bones" co-star Daivd Boreanaz.
Monday's memorial service was invitation-only. Duncan was laid to rest at Forest Lawn Cemetery in the Hollywood Hills.