Several of Ellis' True Blood co-stars were among the 500 people at the event, including Anna Paquin, Carrie Preston and Rutina Wesley, according to the Chicago Sun-Times.
Viola Davis was also in attendance, even speaking during the ceremony, which Ellis' family opened to the public.
“He was like my baby,” Davis said. “When I saw that he was sick, I begged him to get better because I didn’t want to let him go. I still don’t want to let him go.”
Ellis died on July 8 at the age of 39, due to complications from heart failure. His family later revealed Ellis' struggles with alcohol and drug addition, sharing that he was "reluctant to talk about it during his life" but they believed that "in death he would want his life to serve as a cautionary tale in an attempt to help others."