Fox died Oct. 23 of pneumonia, Buena Vista Pictures said in a release Monday.
The St. Louis native's career spanned 50 years through the Golden Age of radio and TV. He first achieved California regional fame in the 1940s with his radio show, "Freddie the Fox," but it was canceled after mothers complained their children were imitating his stutter.
After moving to Hollywood in 1943, he wrote for Burns and Allen, Rosemary Clooney, Jack Carson, Bill Goodwin, Spike Jones, Doris Day and Bing Crosby. He moved over to Bob Hope's staff in 1944 and spent 40 years working with the comic from his days in radio to TV.
Fox also lent his wit to several TV variety shows and sitcoms including "Maude," "All in the Family" and "Alice."
He received a Writer's Guild Award for the "George Burn's Comedy Hour" and co-wrote the film "Oh God, Book II." He was recognized by TV Guide for having three primetime series back to back on the same evening -- "Bob Hope Special," "George Burns Special" and "Love Boat."
Fox is survived by his brother, Henry Fox; his twins, Jan and Fred Jr.; and a granddaughter.