Serie A is a professional football league organized and overseen by the Italian Football Federation. It was founded in 1898 and has been played in the current format since 1929. For most of its history, it consisted of 16 or 18 clubs.

It was in 2004 that number of clubs competing in the top tier of Italian football has been changed to 20 and has remained as such to this day. The elite Italian league is a part of the so-called group of big five European leagues but it has had its ups and downs in the past.