Serie A

Serie A is contested by 20 clubs each season. All 20 clubs play one another twice — once at home, once away — for 38 matches in total. Three points are awarded for a win, one for a draw, and none for a defeat. At the end of the season, the club finishing top of the table are the champions, and they earn the right to wear the scudetto on their shirts the following year. The clubs finishing in the bottom three positions are relegated to Serie B, the second tier.

The modern national league dates to 1929-30, with the main interruption coming during the Second World War. The competition was preceded by earlier formats of the Italian Football Championship dating back to 1898, which later expanded through regional and inter-regional stages before the modern round-robin Serie A was established. The Italian Football Federation officially recognises the pre-1929 champions alongside the Serie A titles, so clubs' all-time title tallies include both eras.

The season usually runs from mid-August to late May, with matches played most weekends and selected fixtures moved to Friday, Monday or other slots for television, European competitions and calendar congestion. Serie A does not always have a fixed winter break, so the exact rhythm of the season can vary from year to year.

For most league positions, clubs level on points are separated first by head-to-head record, then head-to-head goal difference, then overall goal difference, then goals scored.

The main exceptions are the title and the final relegation place. If two clubs finish level in either of those decisive positions, the issue is normally settled by a play-off rather than by the usual tiebreakers. The rules can allow head-to-head to be used instead if a play-off cannot be scheduled because one of the clubs is also due to play a European final. If more than two clubs are tied, the head-to-head mini-table is used to identify the relevant teams.

The three Serie A clubs finishing in the bottom three positions at the end of the season are relegated to Serie B. Serie A does not use a regular end-of-season relegation play-off, but a play-off can be used if clubs finish level on points around the final relegation place. The clubs that replace them come up from Serie B: the top two finishers are promoted automatically, with the third promotion place usually decided by a play-off involving the clubs finishing from third down to eighth, depending on the points gaps in the Serie B table.

The financial gap between Serie A and Serie B is significant, with Serie A clubs receiving considerably more from the league's collective broadcasting deal than Serie B clubs do. The gap has been a source of debate in Italian football for years, with the league exploring various structural changes to keep more competition in the league and to support relegated clubs financially. Several major Italian clubs have spent time in Serie B across the modern era, including Juventus after the 2006 Calciopoli scandal.

The top four Serie A finishers normally qualify automatically for the Champions League league phase. Under UEFA's league-phase format, Italy can receive a fifth Champions League place when its clubs finish among the top two associations for European performance over the previous season, but that extra place changes year by year and is not guaranteed. Below the Champions League places, Europa League and Conference League qualification is shaped by league position, the Coppa Italia and whether cup winners have already qualified for Europe.

The Coppa Italia winners normally qualify for the Europa League. If the cup winners have already qualified for Europe through Serie A, that place passes to the next-best eligible finishers in Serie A. UEFA competition winners can also qualify for Europe through those competitions, so the final number of Italian clubs in Europe can vary.

The first organised Italian football championship was held in 1898 as a small single-day tournament in Turin, won by Genoa. As the competition expanded, it used regional and inter-regional stages before being reorganised into the modern Serie A format for the 1929-30 season. Ambrosiana, the name then used by Internazionale, won the inaugural Serie A title.

Torino dominated the 1940s, but their Il Grande Torino side were lost in the 1949 Superga air disaster, when the aircraft carrying the squad crashed into a hillside on its return from a European friendly. They had won five consecutive Italian league titles. The post-war era saw Juventus, Internazionale, and AC Milan emerge as the three dominant Italian clubs, with sustained periods of dominance for each across the following decades. The 2006 Calciopoli scandal stripped Juventus of the 2004-05 and 2005-06 titles, leaving one season without official winners and awarding the other title to Internazionale. It reshaped the modern competitive landscape, although the basic competition structure remained intact.