NBC Monitor was an American weekend radio program broadcast from June 12, 1955 until January 26, 1975. Airing live and nationwide on the NBC Radio Network, it originally aired beginning Saturday morning at 8am and continuing through the weekend until 12 midnight on Sunday. However, after the first few months, the full weekend broadcast was shortened when the midnight-to-dawn hours were dropped.

The program offered a magazine-of-the-air mix of news, sports, comedy, variety, music, celebrity interviews and other short segments. Its length and eclectic format were radical departures from the traditional radio programming structure of 30- and 60-minute programs and represented an ambitious attempt to respond to the rise of television as America's major home-entertainment medium.

The show was the brainchild of legendary NBC radio and television network president Sylvester (Pat) Weaver, whose career bridged classic radio and television's infancy and who sought to keep radio alive in a television age. Believing that broadcasting could and should educate as well as entertain, Weaver fashioned a series to do both with some of the best-remembered and best-regarded names in broadcasting, entertainment, journalism, and literature taking part. Monitor and the Sunday-afternoon TV documentary series Wide Wide World were Weaver's last two contributions to NBC, as he left the network within a year of Monitor's premiere.

When Monitor began on June 12th, 1955 at 4pm, the first hour of the program was simulcast on NBC-TV. That initial June 12 broadcast lasted eight hours, from 4pm through 12 midnight. Following the Monitor beacon, Morgan Beatty was the first voice ever heard on Monitor. After an introduction by Pat Weaver, news headlines by Dave Garroway and a routine by Bob and Ray, Garroway cued Monitor's opening music remote: live jazz by Howard Rumsey and the Lighthouse All-Stars at the Lighthouse Café in Hermosa Beach, California. It was the first of many jazz remotes in the weeks to come.

On the following Saturday, June 18, Monitor began broadcasting 40 consecutive hours each weekend, from 8am on Saturday to midnight on Sunday. Monitor aired from a mammoth NBC studio called Radio Central, created especially for the program, on the fifth floor of the RCA Building in midtown Manhattan (the same space which is now home to MSNBC). NBC unveiled Radio Central to the national television audience during a segment in the October 16, 1955 premiere of Wide Wide World, including a Monitor interview with Alfred Hitchcock (seen through glass in an adjacent studio and minus audio) and a Monitor newscast (with audio). Built at a cost of $150,000 the glass-enclosed studios of Radio Central were described by Pat Weaver as "a listening post of the world".

From Radio Central, anchors and hosts, initially dubbed "communicators", presided over three or four-hour segments of the show. As well-known entertainment and broadcasting figures, they gave Monitor an impressive marquee. Cindy Adams, Johnny Andrews, Jim Backus, Red Barber, Frank Blair, Bruce Bradley, David Brinkley, Ed Bryce, Art Buchwald, Al "Jazzbo" Collins, Brad Crandall, Bill Cullen, James Daly, Jerry Damon, Dan Daniel, Hugh Downs, Frank Gallop, Dave Garroway, Peter Hackes, Bill Hanrahan, Bill Hayes, Bob Haymes, Candy Jones, Durward Kirby, Jim Lowe, Frank McGee, Barry Nelson, Leon Pearson, Tony Randall, Peter Roberts, Ted Steele, John Cameron Swayze, Tony Taylor and David Wayne were all communicators during the 20-year run.

Many hosts and announcers of game shows were also communicators, including Mel Allen (Jackpot Bowling), Ted Brown, Bill Cullen (The Price Is Right; Eye Guess), Hugh Downs (Concentration), Clifton Fadiman (Information Please), Art Fleming (Jeopardy!), Art Ford (Art Ford Show), Allen Funt, Joe Garagiola (Sale of the Century), Ben Grauer (Information Please), Monty Hall (Video Village; Let's Make a Deal), Wayne Howell (Concentration), Walter Kiernan (Who Said That?), Hal March (The $64,000 Question; What's It For?), Ed McMahon (Concentration; Missing Links; Snap Judgment), Garry Moore (I've Got A Secret; To Tell The Truth), Henry Morgan, Bert Parks (Break the Bank), Gene Rayburn (The Match Game), Don Russell and John Bartholomew Tucker.

In later years Don Imus, Murray the K, Robert W. Morgan and Wolfman Jack helmed the late-night hours until they were eliminated. The last hosts of Monitor in 1975 were Big Wilson and John Bartholomew Tucker. Behind the scenes, Monitor's executive producers included Jim Fleming, Frank Papp, Al Capstaff and Bob Maurer.