Also known as: Pa League

Founded as the Taiheiyo Baseball Union in 1949, it acquired its current name in 1980 and is one of Japan's two major baseball leagues (the other being the Central League). The winner of the league pennant plays the winner of the other league in the Japan Series. The league is comprised of six teams:

- Chiba Lotte Marines (Chiba)
- Fukuoka SoftBank Hawks (Fukuoka)
- Hokkaidou Nippon Ham Fighters (Sapporo)
- Orix Buffaloes (Osaka and Kobe)
- Saitama Seibu Lions (Tokorozawa)
- Touhoku Rakuten Golden Eagles (Sendai)