The broadcaster's son, Keith Harmon, who works with the Milwaukee Brewers radio network, said that his father had been hospitalized for a couple of weeks and died of complications from pneumonia.
The Texas Rangers had a moment of silence before their game Wednesday night in memory of the senior Harmon, who was a broadcaster for the team from 1982 to 1989.
He then retired from broadcasting and settled in Arlington.
The Minnesota Twins also had a moment of silence for Harmon, who called their games from 1967 to 1969.
Harmon, whose broadcasting career began with the minor league Topeka Owls in 1949, called the major league baseball game of the week and college football for ABC Sports in the 1960s, and later did NFL, baseball and college basketball for NBC.
Harmon was a broadcaster for the Milwaukee Brewers from 1970 to 1979, and also worked for baseball's Kansas City A's and the NFL's Kansas City Chiefs and New York Jets during Joe Namath's glory years.
"Merle was a great friend and a wonderful partner in the booth, and the memories he leaves us with will be cherished forever," said Brewers broadcaster Bob Uecker, who was Harmon's partner in the 1970s. "His dedication to family and broadcasting were second to none, and I will always be grateful for the latitude and direction he gave to me as I was entering the profession. . . . This is a very sad day for all of us."
Merle Reid Harmon was born in Salem, Ill., on June 21, 1926. He served in the Navy during World War II and graduated from the University of Denver with a degree in broadcasting.
Harmon and his wife, Jenny, were married more than 50 years. They had four sons and one daughter, and seven grandchildren.
In addition to his broadcasting career, Harmon owned a chain of stores that sold officially licensed sports merchandise -- Merle Harmon's Fan Fair.
He started the business in the 1970s and sold it in 1995. He also was a popular motivational speaker.
Services were pending.