Mr. Harmon, a New York City native, was 94, and his associations in the business reach back to such watershed projects as Show Boat.
He was a founding member of the ATPAM union (listed as a member since 1937) and worked as assistant press rep to impresario Florenz Ziegfeld (1927-28), who produced Show Boat, and also repped producer Mike Todd and the Theatre Guild in his early career. He married writer and radio personality Charlotte Buchwald in 1938.
As a company manager, he worked with such Depression-era Broadway productions as Three Men on a Horse, Bury the Dead, Love From a Stranger and Young Mr. Disraeli.
From 1928 to 1933 he participated in the Vitaphone campaign for Warner Brothers for the early "talkies."
Mr. Harmon and his wife produced seasons at summer theatres in Connecticut, including the Chapel Playhouse in Guilford and the Clinton Playhouse from 1946-57. He also served as a publicist for a handful of summer theatres. As a press agent, he publicized Broadway shows including The Time of Your Life, Something for the Boys, Mexican Hayride, Teahouse of the August Moon, The Entertainer, Sweet Bird of Youth, Fiorello!, West Side Story, The Crucible, A Funny Thing Happened on the Way to the Forum, She Loves Me, Flower Drum Song and Fiddler on the Roof, plus the national tour of Death of a Salesman (1951-52), among many other works.
In later years he was press representative for John Houseman's Juilliard Theater Company and Equity Library Theater.
Mr. Harmon is survived by his wife, Charlotte, a daughter, Jill Boyles, grandchildren Scott and Jennifer, and three great-grandchildren.
Donations can be made in his name to the Actors' Fund of America.