The 1951 World Series matched the two-time defending champion New York Yankees against the New York Giants, who had won the National League pennant in a thrilling three-game playoff with the Brooklyn Dodgers on the legendary home run by Bobby Thomson (the Shot Heard 'Round the World).

In the Series, the Yankees showed some power of their own, including Gil McDougald's grand slam home run in Game 5, at the Polo Grounds. The Yankees won the Series in six games, for their third straight title and 14th overall. This would be the last World Series for Joe DiMaggio, who retired afterward, and the first for rookies Willie Mays and Mickey Mantle.

This was the last Subway Series the Giants played in. Both teams would meet again eleven years later after the Giants relocated to San Francisco. They have not played a World Series together since.

This World Series also matched up two of baseball's most colorful managers, Casey Stengel of the Yankees and Leo Durocher of the Giants.

This was the 13th appearance by the Giants in Series play, their ninth loss, and their first appearance since the 1937 World Series.

The World Series is the annual championship series of Major League Baseball (MLB), played between the American League and National League champions since 1903. The winner of the World Series championship is determined through a best-of-seven playoff and awarded the Commissioner's Trophy. As the series is played in October, Major League Baseball also refers to it as the "Fall Classic". The most recent World Series was won by the St. Louis Cardinals, who defeated the Texas Rangers in 7 games in 2011.

The New York Yankees of the American League have played in 40 World Series and won 27, and the Oakland/Philadelphia Athletics have played in 14 and won 9. In the National League, the St. Louis Cardinals have played in 18 and won 11, while the San Francisco/New York Giants and Los Angeles/Brooklyn Dodgers have both appeared in 18 and won 6.

Until the formation of the American Association in 1882 as a second major league, the National Association of Professional Base Ball Players (1871–75) and then the National League (founded 1876) represented the top level of organized baseball in the United States. All championships went to whoever had the best record at the end of the season, without a postseason series being played. Starting in 1884 and going through 1890, the National League and the American Association faced each other in a series of games at the end of the season to determine an overall champion. These matchups were disorganized in comparison to the modern Series: games played ranged from as few as three in 1884 (Providence defeated New York 3 games to zero), to a high of 15 in 1887 (Detroit beat St. Louis 10 games to 5), and both the 1885 and 1890 Series ended in ties, each team having won three games with one tie game.

Mickey Charles Mantle (October 20, 1931 – August 13, 1995) was an American baseball center fielder who played 18 seasons in Major League Baseball (MLB) for the New York Yankees from 1951 to 1968. Mantle is regarded by many to be the greatest switch hitter of all time, and one of the greatest players in baseball history. Mantle was inducted into the National Baseball Hall of Fame in 1974 and was elected to the Major League Baseball All-Century Team in 1999.

Mantle was noted for his hitting ability, both for average and for power.^{[citation needed]} He won the Triple Crown in 1956, leading MLB in batting average, home runs, and runs batted in (RBI). He received three American League (AL) Most Valuable Player (MVP) Awards and played in twenty All-Star games. Mantle appeared in 12 World Series, winning 7 of them. He holds the records for most World Series home runs (18), RBIs (40), runs (42), walks (43), extra-base hits (26), and total bases (123). He is also the career leader in walk-off home runs, with a combined thirteen, twelve in the regular season and one in the postseason.

Robert Leo "Bob" Sheppard (October 20, 1910 – July 11, 2010) was the long-time public address announcer for numerous New York area college and professional sports teams, in particular the MLB New York Yankees (1951–2007), and the NFL New York Giants (1956–2006).

Sheppard announced more than 4,500 Yankees baseball games over a period of 56 years, including 22 pennant-winning seasons and 13 World Series championships; he called 121 consecutive postseason contests, 62 games in 22 World Series, and six no-hitters, including three perfect games. He was also the in-house voice for a half-century of Giants football games, encompassing 9 conference championships, 3 NFL championships (1956, 1986, 1990), and the game often called "the greatest ever played", the classic 1958 championship loss to Baltimore.

His smooth, distinctive baritone and precise, consistent elocution became iconic aural symbols of both the old Yankee Stadium and Giants Stadium. Reggie Jackson famously nicknamed him "The Voice of God", while Carl Yastrzemski once said, "You're not in the big leagues until Bob Sheppard announces your name."

Robert Brown "Bobby" Thomson (October 25, 1923 – August 16, 2010) was a Scottish-born American professional baseball player. Nicknamed "The Staten Island Scot", he was an outfielder and right-handed batter for the New York Giants (1946–53, 1957), Milwaukee Braves (1954–57), Chicago Cubs (1958–59), Boston Red Sox (1960) and Baltimore Orioles (1960).

His season-ending three-run home run for the Giants in 1951, known as the "Shot Heard 'Round the World", is one of the most famous moments in baseball history. It overshadowed all of his other accomplishments, including eight 20-home run seasons and three All Star selections. "It was the best thing that ever happened to me," he later said. "It may have been the best thing that ever happened to anybody."

Thomson was born in Glasgow, Scotland, the youngest of six children. He arrived in the United States two years later. His father, a cabinet maker, had moved to New York City shortly before Bobby's birth and sent for his family in 1925.

Thomson grew up on Staten Island in New York City and signed with the New York Giants for a $100 bonus right out of Curtis High School in 1942. However, on December 5, 1942 he joined the United States Army Air Forces and trained as a bombardier. His entire service was within the continental United States. In fact, he played semi-professional baseball in the summer of 1945 while awaiting his discharge.