世界大赛（World Series）是美国职棒大联盟每年10月举行的总冠军赛，是美国以及加拿大职业棒球最高等级的赛事。由美国联盟冠军和国家联盟冠军，进行7战4胜制的总冠军赛，（除了1903年、1919年、1920年和1921年，当时采用9战5胜制），获胜的一方获得世界大赛奖杯。自1903年起，除了1904年纽约巨人抵制参加和1994年球员罢工外，世界大赛每年举行。

由于世界大赛基本都在10月举行，因此被许多体育记者称为“秋季经典赛”（Fall Classic）或是“十月经典赛”（October Classic）。世界大赛这个名字常会被误解为是一项洲际赛事，实际只是美国联盟和国家联盟冠军争夺的一项锦标。但由于大联盟能够吸引全世界最好的球员加入，因此最后的冠军也被许多球迷和记者认为是名副其实的世界冠军。

The World Series is the annual championship series of Major League Baseball (MLB) in North America, contested since 1903 between the American League (AL) champion team and the National League (NL) champion team. Prior to 1969, the team with the best win-loss record in each league automatically advanced to the World Series; since then each league has conducted a championship series (ALCS and NLCS) preceding the World Series to determine which teams will advance. As of 2015, the World Series has been contested 111 times, with the AL winning****and the NL winning 47. The winner of the World Series championship is determined through a best-of-seven playoff, and the winning team is awarded the Commissioner's Trophy. As the series is played in October (and occasionally November), during the autumn season in North America, it is often referred to as the Fall Classic.