Formed in 1904 as Società Studio e Divertimento (Society for Study and Entertainment), as a sports club characterised by a black and white striped jersey which was derived from the city of Siena coat of arms.

Today, the name "Robur" is widely used by the local supporters to distinguish itself from the two basketball teams, "Mens Sana" and "Virtus [it]".

After having spent 55 years playing in several lower divisions, Siena were promoted back to Serie B for the start of the 2000–01 season.

The following season, again with Papadopulo as head coach, Siena were promoted to Serie A for the first time officially, led by players such as Rodrigo Taddei and Pinga.

However, a resurgence of form towards of the end of the season gave them hope, and a 2–1 win against already relegated Atalanta on the last day saw them secure safety and an acceptable 14th place in the table.

The club also explored the possibility of changing its denomination to include the name of their main sponsor, Banca Monte dei Paschi di Siena.

[9] In July 2014, thanks to the article 52 of N.O.I.F., the club was refounded under new legal person società sportiva dilettantistica Robur Siena, restarting from 2014–15 Serie D.[10] It was promoted to 2015–16 Lega Pro as champions of Group E in June 2015.

In the 2015–16 season, Robur won the regional derby against Pisa at the Garibaldi Arena[11] after 57 years and qualified for semifinal of Coppa Italia Lega Pro against Foggia, winning the first leg at home, 5–2.

[14][15] The club was then readmitted to Serie C in 2021 to fill a vacancy, and then sold to Italian group Global Service in June 2022.

[18] The Mayor of Siena subsequently handed the sports title to Atlas Consulting srl, former owners of Triestina, who will lead the new club in the Eccellenza league.

Other historic city anthems such as the Canto della Verbena and the Marcia del Palio are often sung by local fans during the matches.