As with the introduction of baseball in other countries, its roots in Japan date back to the 1870s. Legend has it that the sport was first introduced to local Japanese students by an American professor, Dr. Horace Wilson, in 1872.

One major difference between American and Japanese professional baseball is that in Japan, a regular-season game can end in a tie. If a game is tied at the end of 9 innings, up to 3 additional extra innings are played. After 12 innings if the game still remains tied, no winner is declared.

For the turn of the 20th century to the 1930s, the Big Six University League was Japan's version of the United States' major leagues. The status of baseball drastically changed in Japan in 1934, when an American All-Star team, featuring such greats as babe Ruth and Lou Gehrig, toured Japan. Needless to say, the college-age Japanese ballplayers were put to shame by the American All-Stars. Since honor is such an integral part of Asian culture, Japan's baseball standards were thought to be too lax and in desperate need of some professionalism; in steps Japanese business tycoon, Matsutaro Shoriki.

In 1934, Shoriki established Japan's first professional baseball club, the Great Tokyo Baseball Club. It is later renamed the Tokyo Kyojin (Giants).

In 1936, Matsutaro Shoriki was responsible for establishing Japan's first professional baseball league, The Japan Professional Baseball League (JPBL). Its founding members were: the Osaka Tigers, the Tokyo Giants, Hankyu, Dai Tokyo, Nagoya Kinko, Nagoya and the Tokyo Senators. The use of English was banned. Hence, the Osaka Tigers were renamed the Hanshin, and the Tokyo Senators the Tsubasa.

The league ran successfully through WWII. As with other nations, baseball took a back seat to the war efforts. In 1946, the league resumed with two new teams, the Goldstar and the Senators. Once WWII had come to an end, the use of English in Japan was prevalent. Every Japanese baseball team had adopted English nicknames. Seven new teams were founded, hence the introduction of a two-league system. In 1950, both the Central and Pacific baseball leagues were established.  

The Central League comprised: the Giants, Tigers, Dragons, Kokutetsu Swallows, Hisroshima Carp, Taiyo Whales, Nishi-Nippon Pirates and the Shochiku Robins. The Pacific League included: the Mainichi Orions, Lions, Hankyu Braves, Tokyu Flyers, Nankai Hawks, Kintetsu Pearls and the Daiei Stars. The Pacific League models itself after the U.S. American League, in that it uses designated hitters, while the Central League does not.

In 1953, the Robins and Whales merged. A new team, the Takahsahi Unions, joined the Pacific League in 1954. However, in 1956, they merged with the Stars. After one season, the Daiei Unions and the Orions merged. In 1958, all was settled and each league was comprised of six teams.

The Japanese Baseball Hall of Fame and Museum was established in 1959, in Tokyo. The first group of inductees included: Matsutaro Shoriki, Hiroshi Hiroka, Yokio Aoi, Isoo Abe, Shin Hashido, Kiyoshi Oshikawa, Jiro Kuji. Eiji Awamura, and Michimaro Ono.

In 1964 Joe Stanka is the first American player to win the MVP award of the Pacific League.

Almost from its inception the Giants were clearly the team to beat. Their founder, Shoriki was the wealthiest of all of the owners and used this to purchase the best players. In the hopes of leveling the playing field, a draft was established in 1965.

On September 18, 2004, professional Japanese baseball players went on a 2-day strike. It was the first in Japanese history.  The purpose of the strike to protest the potential merger between the Orix BlueWave and the Osaka Kintestu Buffaloes. The Strike ended on September 23, when the owners agreed to grant the Pacific league a new franchise.