Major League Baseball (MLB) is the most historic professional sports league in the United States and consists of 30 member clubs in the U.S. and Canada, representing the highest level of professional baseball.

Major League Baseball is the best-attended sport in North America. The last decade includes all 10 of the best-attended individual seasons by fans in MLB history, with each regular season eclipsing the 73 million mark.

Now led by Commissioner Robert D. Manfred, Jr., MLB currently features record levels of labor peace, competitive balance and industry revenues, as well as the most comprehensive drug-testing program in American professional sports.