AC Siena has been a regular Serie A team the last 10 years, but that is something very new for the Tuscan team. It was actually the club's first ever promotion to Serie A when the black/whites achieved this in 2003. Siena play their home matches at Stadio Artemio Franchi, not to get confused with the stadium of same name in Florence, where Fiorentina play.

The team was founded in 1904 as "Società Studio e Divertimento" (Society for Sports and Education), while it changed to "Società Sportiva Robur" in 1908 so the fans could differ the football team for the two other basket teams: Mens Sana and Virtus. "Robur" is still used as a nickname for AC Siena. The final and latest change was in 1933/1934 where the name was changed to Associazione Calcio Siena. The team tried to change their name in 2007 to AC Siena Montepaschi due to their sponsor: the oldest bank in the world Monte dei Paschi di Siena. FIGC refused this, so the name remained AC Siena. 

Siena has in their life-time spent most of the time in Serie C: 49 seasons, where the last season spent there was in 1999/2000, the same year Lazio won the Scudetto, where they the same year won their only trophy so far: Supercoppa di Lega di Serie C1. The golden season is considered the 2002/03 season where the team reached promotion to Serie A for the first time in their long history. The promotion is strongly linked to the president of the time: Paolo De Luca, who took over the club in 2001. In their first season in Serie A they reached a respectable 13th spot with players such as Enrico Chiesa, Tore Andre Flo and Nicola Ventola.

The team hereafter had some struggling seasons in Serie A before they relegated in the 2009/10 season. During this seasin Massimo Mezzaroma became the new president of Siena. This time it was a short trip to the second divison as Siena ended runner-up to Atalanta in Serie B and returned to Serie A for the 2011/12 season.