In Major League Baseball (MLB), the 500 home run club is a group of batters who have hit 500 or more regular-season home runs in their careers. On August 11, 1929, Babe Ruth became the first member of the club. Ruth ended his career with 714 home runs, a record which stood from 1935 until Hank Aaron surpassed it in 1974. Aaron's ultimate career total, 755, remained the record until Barry Bonds set the current mark of 762 during the 2007 season. Twenty-eight players are members of the 500 home run club. Ted Williams (.344) holds the highest batting average among the club members while Harmon Killebrew (.256) holds the lowest.

Of these 28 players, 15 were right-handed batters, 11 were left-handed, and 2 were switch hitters. The San Francisco Giants and Boston Red Sox are the only franchises to see four players reach the milestone while on their roster: for the Giants, Mel Ott while the team was in New York, Willie Mays, Willie McCovey, and most recently Bonds, and, for the Red Sox, Jimmie Foxx, Williams, and more recently Manny Ramirez and David Ortiz. Seven 500 home run club membersAaron, Mays, Eddie Murray, Rafael Palmeiro, Albert Pujols, Alex Rodriguez and Miguel Cabreraare also members of the 3,000 hit club. Gary Sheffield's 500th home run was his first career home run with the New York Mets, the first time that a player's 500th home run was also his first with his franchise. Rodriguez, at 32 years and 8 days, was the youngest player to reach the milestone while Williams, at 41 years and 291 days, was the oldest. The most recent player to reach 500 home runs is Miguel Cabrera, who hit his 500th home run on August 22, 2021. Pujols and Cabrera are the only active members of the 500 home run club. Six members of the club were born outside of the United States: Sammy Sosa, Ramirez, Pujols and Ortiz in the Dominican Republic; Palmeiro in Cuba, and Cabrera in Venezuela.

Membership in the 500 home run club is sometimes described as a guarantee of eventual entry into the Baseball Hall of Fame, although some believe the milestone has become less meaningful in recent years. Seven eligible club membersBonds, Rodriguez, Mark McGwire, Palmeiro, Ramirez, Sheffield and Sosahave not been elected to the Hall. Bonds and Sosa made their first appearance on the Hall of Fame ballot in 2013; Bonds received only 36.2% and Sosa 12.5% of the total votes, with 75% required for induction. Eligibility requires that a player has "been retired five seasons" or be deceased for at least six months. Some believe the milestone has become less important with the large number of new members; 10 players joined the club from 1999 to 2009. Additionally, several of these recent members have had ties to performance-enhancing drugs. Some believe that by not electing McGwire to the Hall the voters were establishing a "referendum" on how they would treat players from the "Steroid Era". On January 8, 2014, Palmeiro became the first member of the club to be removed from the BBWAA Hall of Fame ballot. As the BBWAA announced the selections for the Baseball Hall of Fame Class of 2014, Palmeiro appeared on just 4.4% of the ballots. Players must be named on at least of 5.0% of ballots to remain on future ballots.

George Herman "Babe" Ruth Jr. (February 6, 1895 – August 16, 1948) was an American professional baseball player whose career in Major League Baseball (MLB) spanned 22 seasons, from 1914 through 1935. Nicknamed "The Bambino" and "The Sultan of Swat", he began his MLB career as a star left-handed pitcher for the Boston Red Sox, but achieved his greatest fame as a slugging outfielder for the New York Yankees. Ruth is regarded as one of the greatest sports heroes in American culture and is considered by many to be the greatest baseball player of all time. In 1936, Ruth was elected into the Baseball Hall of Fame as one of its "first five" inaugural members.

At age seven, Ruth was sent to St. Mary's Industrial School for Boys, a reformatory where he was mentored by Brother Matthias Boutlier of the Xaverian Brothers, the school's disciplinarian and a capable baseball player. In 1914, Ruth was signed to play minor-league baseball for the Baltimore Orioles but was soon sold to the Red Sox. By 1916, he had built a reputation as an outstanding pitcher who sometimes hit long home runs, a feat unusual for any player in the pre-1920 dead-ball era. Although Ruth twice won 23 games in a season as a pitcher and was a member of three World Series championship teams with the Red Sox, he wanted to play every day and was allowed to convert to an outfielder. With regular playing time, he broke the MLB single-season home run record in 1919.

After that season, Red Sox owner Harry Frazee sold Ruth to the Yankees amid controversy. The trade fueled Boston's subsequent 86-year championship drought and popularized the "Curse of the Bambino" superstition. In his 15 years with the Yankees, Ruth helped the team win seven American League (AL) pennants and four World Series championships. His big swing led to escalating home run totals that not only drew fans to the ballpark and boosted the sport's popularity but also helped usher in baseball's live-ball era, which evolved from a low-scoring game of strategy to a sport where the home run was a major factor. As part of the Yankees' vaunted "Murderers' Row" lineup of 1927, Ruth hit 60 home runs, which extended his MLB single-season record by a single home run. Ruth's last season with the Yankees was 1934; he retired from the game the following year, after a short stint with the Boston Braves. Throughout his career, Ruth led the AL in home runs during a season 12 times.

During Ruth's career, he was the target of intense press and public attention for his baseball exploits and off-field penchants for drinking and womanizing. After his retirement as a player, he was denied the opportunity to manage a major league club, most likely due to poor behavior during parts of his playing career. In his final years, Ruth made many public appearances, especially in support of American efforts in World War II. In 1946, he became ill with nasopharyngeal cancer and died from the disease two years later. Ruth remains a part of American culture, and in 2018 President Donald Trump posthumously awarded him the Presidential Medal of Freedom.