The following article details the history of Major League Baseball on NBC, the broadcast of Major League Baseball games on the NBC television network.

Early years 1930s NBC television's relationship with Major League Baseball technically dates back to August 26, 1939. It was on that date that on W2XBS (an experimental television station in New York City which would ultimately become what is now NBC's flagship television station, WNBC), the first-ever Major League Baseball game was televised. With Red Barber announcing, the Brooklyn Dodgers and the Cincinnati Reds played a doubleheader at Ebbets Field. The Reds won the first game 5–2 while the Dodgers won the second, 6–1. Barber called the game without the benefit of a monitor and with only two cameras capturing the game. One camera was on Barber and the other was behind the plate. Barber had to guess from which light was on and where it pointed.

1940s By 1947, television sets, most with five and seven-inch screens, were selling almost as fast as they could be produced. Because of this, Major League teams began televising games and attracted a whole new audience into ballparks in the process. People who had only casually followed baseball began going to the games in person. In 1948, Major League Baseball's total attendance reached a record high of 21 million.

1947 also saw the first televised World Series. The games were broadcast in the New York City area by NBC's WNBT, CBS's WCBS-TV and DuMont's WABD and sponsored by Gillette and Ford. The 1947 World Series brought in an estimated 3.9 million viewers, becoming television's first mass audience. In addition to New York City, live coverage of the Series was also seen on WRGB in Schenectady/Albany (now a CBS affiliate), WPTZ (now CBS-owned KYW-TV) in Philadelphia, WMAR-TV in Baltimore and WTTG in Washington, D.C.

In 1948 and 1949, the World Series would be carried on the aforementioned stations, as well as on WBZ-TV and WNAC-TV (now WHDH-TV) in Boston, WNHC-TV (now WTNH) in New Haven and WTVR-TV in Richmond, Virginia. In 1949, the World Series was also seen live in other Northeastern and Midwestern cities (Harrisburg, Pittsburgh, Syracuse, Rochester, Buffalo, Erie, Cleveland, Detroit, Columbus, Cincinnati, Dayton, Toledo, Indianapolis, Chicago, Milwaukee and St. Louis) that had been hooked up to network lines over the previous year.

1950s In 1950, the Mutual Broadcasting System acquired the television as well as radio broadcast rights to the World Series and All-Star Game for the next six years. Mutual may have been reindulging in dreams of becoming a television network or simply taking advantage of a long-standing business relationship; in either case, the broadcast rights were sold to NBC in time for the following season's games at an enormous profit.

By , World Series games could be seen in most of the country, but not all. 1950 also marked the first time that there was an exclusive network television broadcaster (NBC). West Coast viewers finally saw live major league games on television during the 1951 postseason.

NBC aired the second and third games of the 1951 National League tie-breaker series between the Brooklyn Dodgers and New York Giants, necessitated by the teams' finishing the regular season in a tie for first place. The three-game pennant playoff, which featured the first baseball games televised live from coast to coast (with CBS airing the first game), culminated on October 3 when the Giants won the third and deciding game by the score of 5–4 (off Bobby Thomson's home run). Ernie Harwell called the game for Giants television flagship WPIX – the independent station's broadcast was simulcast nationally by NBC – and his description of the home run was a simple shout of "It's gone!" almost at the moment Thomson's bat struck Ralph Branca's pitch. Harwell later admitted he had probably called it "too soon", but fortunately for him, the call proved to be correct. "And then", Harwell recalled, "the pictures took over."

The 1951 playoff between Brooklyn and the New York Giants and that year's World Series were the first major league baseball games telecast live from coast-to-coast to coast; transcontinental network transmission lines had been completed and activated in September, in-time for the Japanese Peace Treaty Conference in San Francisco and the start of the 1951–52 television season.

The 1952 All-Star Game at Shibe Park in Philadelphia was the first nationally televised All-Star Game, but it was shortened due to rain.

On January 31, 1953, the New York Yankees, Cleveland Indians and Boston Red Sox joined forces against St. Louis Browns owner Bill Veeck. The respective franchises tried to force the Browns to play afternoon games in an attempt to avoid having to share television revenues. A month later, Major League Baseball owners received a warning from Senator Edwin Johnson about nationally televising their games. Johnson's theory was that nationally televising baseball games would be a threat to the survival of minor league baseball. The owners ignored Johnson, as the games on NBC were gaining a large and loyal following.

Another first for NBC during this period was the first color telecast of a World Series, the 1955 matchup between the Brooklyn Dodgers and the New York Yankees.

Chicago White Sox announcer Bob Elson missed a chance to call the 1959 World Series – the White Sox' first since 1919, and Elson's first since 1943 – on NBC because the then head of NBC Sports, Tom Gallery (who incidentally, grew up on the same block as Elson) did not like him. Elson was, however, allowed to call the Series on the White Sox' radio flagship, WCFL.

NBC begins airing the Game of the Week (1957–65) In 1957, NBC started airing weekend Game of the Week telecasts (Sunday telecasts were added in 1959) with Lindsey Nelson and Leo Durocher calling the action. During this period, NBC (as rival CBS had the rights to broadcast at least eight teams) typically broadcast from Pittsburgh's Forbes Field, Chicago's Wrigley Field or Milwaukee's County Stadium. NBC purchased the rights to 11 Milwaukee Braves games, 11 Pittsburgh Pirates games, two Washington Senators games, and two Chicago Cubs games. Leo Durocher was succeeded as color commentator by Fred Haney in 1960, and Joe Garagiola in 1961, while Bob Wolff replaced Nelson on play-by-play in 1962.

From 1958 to 1960, NBC aired a special regional feed of its games in the southeast, where the network had a different sponsor (such as National Bohemian beer) than for the rest of the country. This feed featured its own announcing team, with Chuck Thompson calling the games with Bill Veeck (1958) and Al Rosen (1959–60). NBC never had a true backup game until 1966, when the network got exclusivity for the Game of the Week. In the process, NBC brought in Curt Gowdy and Pee Wee Reese for the primary game, and Jim Simpson and Tony Kubek for the alternate game (which was always shown in the markets of teams playing in the primary game).

1960–65 As previously mentioned, in 1961, NBC hired Joe Garagiola to be their Major League Baseball color commentator. The following year, Bob Wolff began working play-by-play. "You work your side of the street [interviewing players]", said Garagiola to Wolff "and I'll work mine." Wolff liked Garagiola's pizazz as he would say things like "the guy stapled him to the bag" or that a runner is "smilin' like he swallowed a banana peel." Also in 1962, NBC broadcast the National League tie-breaker series between the San Francisco Giants and Los Angeles Dodgers. Bob Wolff and George Kell were the announcers for the playoff series. Wolff also hosted the pre-game shows for NBC's World Series coverage from 1962 to 1965.

Prior to the mid-1970s, television networks and stations generally did not preserve telecasts of sporting events, choosing instead to tape over them. As a result, the broadcasts of six of the seven 1960 World Series games are no longer known to exist. The lone exception is a black-and-white kinescope of the entire telecast of Game 7, which was discovered in a wine cellar in Bing Crosby's home in Hillsborough, California in December 2009. A part-owner of the Pittsburgh Pirates, who was too superstitious to watch the Series live, Crosby listened to the decisive contest with his wife Kathryn and two friends on a shortwave radio in Paris, France. Wanting to watch the game at a later date only if the Pirates won, he arranged for a company to record it. After viewing the kinescope, he placed it in his wine cellar, where it went untouched for 49 years. It was finally found by Robert Bader, vice president of marketing and production for Bing Crosby Enterprises, while looking through videotapes of Crosby's television specials which were to be transferred to DVD. The five-reel set is the only known complete copy of the historic match, which was originally broadcast in color. The NBC television announcers for the Series were Bob Prince and Mel Allen, the respective primary play-by-play voices for the Pirates and New York Yankees. Prince called the first half of Game 7, while Allen did the latter portion.

In contrast to preceding years, where NBC's World Series telecasts featured two announcers (usually one from each participating team) who split the play-by-play duties, each working his portion of the game by himself, in 1961, the network had Yankees announcer Mel Allen handle all of the play-by-play on television (with Reds announcer Waite Hoyt confined to radio) while Joe Garagiola provided color commentary. This format would eventually become the standard form of presentation on World Series telecasts. In Week 3 of the 1961 National Football League season, the Baltimore-Green Bay game was televised locally to Baltimore over NBC affiliate WBAL-TV. Apparently if Baltimore viewers wanted to see the World Series, they would have had to choose between NBC-owned WRC-TV in Washington or affiliate WGAL-TV in Lancaster, Pennsylvania. There was no NFL telecast on NBC (who at the time broadcast Pittsburgh Steelers and Colts games) due to coverage of Game 4 of the World Series.

On July 13, 1963, NBC's coverage of the Detroit Tigers–Chicago White Sox game from Comiskey Park in Chicago was carried by KCRA-TV in Sacramento, KCRL in Reno and KVIP-TV in Redding – however it was not televised in the San Francisco market on KRON-TV. NBC's coverage of the Cleveland Indians-Tigers game at 11:30 a.m. the following day was also not broadcast by KRON.

During the fourth and final game of the World Series, Yankees announcer Mel Allen was calling the top of the ninth inning for NBC when his voice gave out due to a bout of severe laryngitis, forcing Dodgers announcer Vin Scully (who had called the first four-and-a-half innings of the game per the network's usual setup) to resume play-by-play duties for the remainder of the game. After the Series New York Daily News sportswriter Dick Young opined that Allen, the voice of the Yankees, had been stricken by "psychosomatic laryngitis" caused by his team being swept.

By 1964, CBS' Dizzy Dean and Pee Wee Reese called games from Yankee Stadium, Wrigley Field, St. Louis, Philadelphia and Baltimore. New York got a US$550,000 payment of CBS' $895,000. Meanwhile, six clubs that exclusively played nationally televised games on NBC were paid $1.2 million.