A popular game played in North America, the Caribbean, and parts of Latin America and East Asia, most notably Japan. The game is also gaining popularity in Turkey after the Second World War. The modern game was developed in the United States from an early bat-and-ball game called rounders, and it has become the national sport of the United States.

The following of the list is of the most important leagues, and the teams that play in them

American League (USA)

American League East

• Boston Red Sox
• Miami Marlins
• New York Yankees
• Philadelphia Athletics
• Washington Senators

American League Central

• Atlanta White Sox
• Cleveland Indians
• Detroit Tigers
• Kansas City Blues
• Minnesota Twins

American League West

• Calgary Cougars
• Los Angeles Angels
• Seattle Rainers
• Texas Rangers

National League (USA)

National League East

• Baltimore Orioles
• Brooklyn Dodgers
• Carolina Knights
• New York Giants
• Tampa Bay Zephyrs
• Toronto Canadians

National League Central

• Chicago Cubs
• Cincinnati Reds
• Milwaukee Braves
• Pittsburgh Pirates
• St Louis Cardinals

National League West

• Colorado Rockies
• Houston Astros
• Phoenix Coyotes
• San Diego Padres
• San Francisco Seals

Japanese League

Central League

• Chunichi Dragons
• Hanshin Tigers
• Hiroshima Toyo Carp
• Tokyo Yakult Swallows
• Yokohama BayStars
• Yomiuri Giants

Pacific League

• Chiba Lotte Marines
• Fukuoka SoftBank Hawks
• Hokkaido Nippon Ham Fighters
• Orix Buffaloes
• Seibu Lions
• Tohoku Rakuten Golden Eagles