The Hunger Games star played dim-witted barman Woody Boyd on the show from 1985 to 1993 and he insists an official cast get together is long overdue.
He tells Britain's Daily Express newspaper, "It's something I get asked about now and again. A lot of people have fond memories of that show and it is still huge around the world.
"It might be fun to get us all back together before we all get too old. Maybe it could be Cheers: The Movie."
Ted Danson, Shelley Long, Rhea Perlman, Kelsey Grammer and Kirstie Alley all co-starred with Harrelson on the show, set in a bar in Boston, Massachusetts.