| Club: | Siena |
| Season: | 2011–12 |
| Chairman: | Massimo Mezzaroma |
| Chrtitle: | President |
| Manager: | Giuseppe Sannino |
| Mgrtitle: | Head Coach |
| Stadium: | Stadio Artemio Franchi |
| League: | Serie A |
| League Result: | 14th |
| Cup1: | Coppa Italia |
| Cup1 Result: | Semi-finals |
| League Topscorer: | Mattia Destro (12) |
| Season Topscorer: | Mattia Destro (13) |
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| Prevseason: | 2010–11 |
| Nextseason: | 2012–13 |
The 2011–12 season was Associazione Calcio Siena's 106th in existence and 8th season in the top flight of Italian football, Serie A.
Players and squad numbers last updated on 30 May 2012.[1] Note: Flags indicate national team as has been defined under FIFA eligibility rules. Players may hold more than one non-FIFA nationality.
| No. | Name | Nationality | Position | Date of Birth (Age) | Signed from | Notes | |
|---|---|---|---|---|---|---|---|
| Goalkeepers | |||||||
| 1 | Željko Brkić | GK | 1986 7, df=yes | Udinese | on loan from Udinese | ||
| 12 | Simone Farelli |  | GK | 1983 2, df=yes | Crotone | ||
| 25 | Gianluca Pegolo | | GK | 1981 3, df=yes | Genoa | ||
| Defenders | |||||||
| 2 | Roberto Vitiello | | RB | 1983 5, df=yes | Rimini | ||
| 4 | Cristiano Del Grosso | | LB | 1983 3, df=yes | Cagliari | ||
| 13 | Luca Rossettini | | CB | 1985 5, df=yes | Padova | ||
| 15 | Nicola Belmonte | | RB | 1987 4, df=yes | Bari | ||
| 19 | Claudio Terzi | | CB | 1984 6, df=yes | Bologna | ||
| 21 | Andrea Rossi | | LB | 1986 11, df=yes | Juventus Primavera | ||
| 26 | Emanuele Pesoli | | CB | 1980 8, df=yes | Varese | ||
| 80 | Matteo Contini | | CB | 1980 4, df=yes |  Zaragoza | on loan from Zaragoza | |
| Midfielders | |||||||
| 5 | Paul Codrea | CM | 1981 4, df=yes | Palermo | |||
| 6 | Ângelo |  | MF | 1981 6, df=yes | Parma | ||
| 7 | Luigi Giorgi | | MF | 1987 4, df=yes | Novara | on loan from Novara | |
| 8 | Simone Vergassola | | DM | 1976 1, df=yes | Torino | Captain | |
| 10 | Gaetano D'Agostino | | MF | 1982 6, df=yes | Fiorentina | ||
| 14 | Alessandro Gazzi | | MF | 1983 1, df=yes | Bari | ||
| 17 | Paolo Grossi | | LW | 1985 5, df=yes | AlbinoLeffe | ||
| 20 | Joel Acosta |  | MF | 1991 1, df=yes | Boca Juniors | on loan from Boca Juniors | |
| 36 | Francesco Bolzoni | | CM | 1989 5, df=yes | Genoa | ||
| 55 | Francesco Parravicini | | CM | 1982 1, df=yes | Parma | ||
| 70 | Daniele Mannini | | RW | 1983 10, df=yes | Sampdoria | ||
| 77 | Alessio Sestu | | MF | 1983 9, df=yes | Vicenza | ||
| Forwards | |||||||
| 9 | Marcelo Larrondo | | ST | 1988 8, df=yes | Progrese | ||
| 11 | Emanuele Calaiò | | ST | 1982 1, df=yes | Napoli | Vice-captain | |
| 14 | Pablo González | | FW | 1985 5, df=yes | Palermo | on loan from Palermo | |
| 22 | Mattia Destro | | ST | 1991 3, df=yes | Genoa | on loan from Genoa | |
| 23 | Franco Brienza | | FW | 1979 3, df=yes | Reggina | ||
| 32 | Erjon Bogdani |  | ST | 1977 4, df=yes | Cesena | ||
| Players transferred during the season | |||||||
| 7 | Gennaro Troianiello | | MF | 1983 3, df=yes | Frosinone | on loan to Sassuolo | |
| 27 | Milan Milanović |  | CB | 1991 3, df=yes | Palermo | recalled from loan by Palermo | |
| 33 | Gabriele Angella | | CB | 1989 4, df=yes | Udinese | recalled from loan by Udinese | |
| 83 | Reginaldo | | FW | 1983 7, df=yes | Parma | on loan to  JEF United Ichihara Chiba | |
| 89 | Mihail Ivanov |  | GK | 1989 8, df=yes | Youth System | on loan to Piacenza | |
For a list of all A.C. Siena transfers, see List of Italian football transfers winter 2011–12, List of Italian football transfers summer 2011 (July), List of Italian football transfers summer 2011 (August), List of Italian football transfers summer 2011 (co-ownership)
Substitute appearances off of the bench appear only in parentheses.
| No. | Pos. | Name | League | Coppa Italia | Total | Discipline | ||||
|---|---|---|---|---|---|---|---|---|---|---|
| Apps | Goals | Apps | Goals | Apps | Goals | |||||
| 1 | GK | Željko Brkić | 18 | 0 | 2 | 0 | 20 | 0 | 1 | 0 |
| 2 | DF | Roberto Vitiello | 33 | 1 | 1(1) | 0 | 34(1) | 1 | 7 | 0 |
| 3 | DF | Cristiano Del Grosso | 31(1) | 2 | 1 | 0 | 32(1) | 2 | 7 | 0 |
| 5 | MF | Paul Codrea | 0(1) | 0 | 1(1) | 0 | 1(2) | 0 | 0 | 0 |
| 6 | MF | Ângelo | 7(6) | 0 | 5 | 2 | 12(6) | 2 | 1 | 0 |
| 7 | MF | Luigi Giorgi | 12(1) | 1 | 0(1) | 0 | 12(2) | 1 | 3 | 0 |
| 7 | MF | Gennaro Troianiello | 0 | 0 | 2 | 0 | 2 | 0 | 0 | 0 |
| 8 | MF | Simone Vergassola | 23(6) | 0 | 2 | 0 | 25(6) | 0 | 3 | 0 |
| 9 | FW | Marcelo Larrondo | 6(8) | 1 | 2(2) | 0 | 8(10) | 1 | 3 | 0 |
| 10 | MF | Gaetano D'Agostino | 19(5) | 3 | 2 | 1 | 21(5) | 8 | 7 | 0 |
| 11 | FW | Emanuele Calaiò | 24(1) | 11 | 1 | 1 | 25(1) | 12 | 5 | 0 |
| 12 | GK | Simone Farelli | 1 | 0 | 2 | 0 | 3 | 0 | 0 | 0 |
| 13 | DF | Luca Rossettini | 30(1) | 1 | 2 | 0 | 32(1) | 1 | 11 | 0 |
| 14 | MF | Alessandro Gazzi | 31(2) | 1 | 2 | 0 | 33(2) | 1 | 7 | 0 |
| 15 | DF | Nicola Belmonte | 1(1) | 0 | 4 | 0 | 5(1) | 0 | 0 | 0 |
| 17 | MF | Paolo Grossi | 9(8) | 1 | 2 | 0 | 11(8) | 1 | 1 | 1 |
| 18 | FW | Pablo González | 5(11) | 1 | 3(1) | 2 | 8(12) | 3 | 1 | 0 |
| 19 | DF | Claudio Terzi | 33(2) | 1 | 2(1) | 0 | 35(3) | 1 | 12 | 0 |
| 20 | MF | Joel Acosta | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| 21 | DF | Andrea Rossi | 7(3) | 0 | 5 | 0 | 12(3) | 0 | 7 | 0 |
| 22 | FW | Mattia Destro | 26(4) | 12 | 1(1) | 1 | 27(5) | 13 | 5 | 0 |
| 23 | FW | Franco Brienza | 34(2) | 4 | 2(1) | 0 | 36(3) | 4 | 4 | 1 |
| 25 | GK | Gianluca Pegolo | 19 | 0 | 2 | 0 | 21 | 0 | 1 | 1 |
| 26 | DF | Emanuele Pesoli | 7(2) | 0 | 4 | 0 | 11(2) | 0 | 4 | 0 |
| 33 | DF | Gabriele Angella | 0 | 0 | 0(2) | 0 | 0(2) | 0 | 0 | 0 |
| 36 | MF | Francesco Bolzoni | 8(8) | 1 | 2(2) | 0 | 10(10) | 1 | 2 | 0 |
| 55 | MF | Francesco Parravicini | 1(8) | 0 | 3(1) | 0 | 4(9) | 0 | 3 | 0 |
| 70 | MF | Daniele Mannini | 12(9) | 0 | 3 | 0 | 15(9) | 0 | 4 | 0 |
| 77 | MF | Alessio Sestu | 1(4) | 0 | 0(3) | 0 | 1(7) | 0 | 1 | 0 |
| 80 | DF | Matteo Contini | 12(4) | 0 | 4 | 0 | 16(4) | 0 | 4 | 0 |
| 81 | FW | Erjon Bogdani | 4(7) | 4 | 1(1) | 0 | 5(8) | 4 | 0 | 0 |
| 83 | FW | Reginaldo | 4(9) | 0 | 5 | 3 | 9(9) | 3 | 1 | 0 |