| Competition: | Serie A |
| Dates: | 30 August 2008 – 31 May 2009 |
| Season: | 2008–09 |
| Winners: | Internazionale 17th title |
| Relegated: | Torino Reggina Lecce |
| Continentalcup1: | Champions League |
| Continentalcup1 Qualifiers: | Internazionale Juventus Milan Fiorentina |
| Continentalcup2: | Europa League |
| Continentalcup2 Qualifiers: | Genoa Roma Lazio |
| League Topscorer: | Zlatan Ibrahimović (25 goals) |
| Biggest Home Win: | Sampdoria 5–0 Reggina |
| Biggest Away Win: | Roma 0–4 Internazionale Siena 1–5 Milan Palermo 0–4 Catania |
| Highest Scoring: | Udinese 6–2 Cagliari |
| Matches: | 380 |
| Total Goals: | 988 |
| Average Attendance: | 25,324 |
| Prevseason: | 2007–08 |
| Nextseason: | 2009–10 |
The 2008–09 Serie A (known as the Serie A TIM for sponsorship reasons) was the 107th season of top-tier Italian football, the 77th in a round-robin tournament. It began on 30 August 2008 and ended on 31 May 2009, with the announcement of the list of fixtures made on 25 July 2008. 20 teams competed in the league, 17 of which returned from the previous season, and three (Chievo, Bologna and Lecce) were promoted from 2007–08 Serie B.
20 clubs represented 13 different regions. The most represented region was Lombardy with three teams: Atalanta, A.C. Milan, and Inter Milan. Piedmont, Liguria, Tuscany, Lazio and Sicily featured two teams each while Friuli-Venezia Giulia, Veneto, Emilia-Romagna, Campania, Apulia, Calabria, and Sardinia were represented by one team each. There was a record number of southern teams in the top division with six teams: Cagliari, Catania, Lecce, Napoli, Palermo, and Reggina.
The new match ball was the Nike T90 Omni.
On 16 May 2009, Internazionale won the league by holding an unassailable lead after A.C. Milan's loss away to Udinese.
The 2008–09 season saw new rules relating to the transfer of player registration introduced. Clubs without non-EU players in their squad were allowed three incoming non-EU player transfers (whereas previously only newly promoted clubs could have three). Clubs with one non-EU player were allowed two such transfers and clubs with two non-EU players were permitted one transfer and a further one if they cancelled the registration of one of their non-EU players or that player gained EU nationality. Clubs with three or more non-EU players were given two conditional quotas with the caveat that the release (as opposed to transfer) of two non-EU players as free agent would only allow for one further non-EU signing.[1]
Three teams were promoted from Serie B: Chievo, Bologna, and Lecce. The first two earned direct promotion, while Lecce won the promotional playoffs, defeating AlbinoLeffe 2–1 on aggregate in a two-legged playoff final.
| Team | Outgoing manager | Manner of departure | Date of vacancy | Replaced by | Date of appointment | |
|---|---|---|---|---|---|---|
| Siena |  Mario Beretta[2] | Contract expired | 27 May 2008 | Marco Giampaolo | 27 May 2008 | |
| Cagliari | Davide Ballardini[3] | Contract expired | 27 May 2008 | Massimiliano Allegri[4] | 29 May 2008 | |
| Internazionale | Roberto Mancini[5] | Sacked | 29 May 2008 | José Mourinho[6] | 2 June 2008 | |
| Lecce | Giuseppe Papadopulo[7] | Contract expired | 23 June 2008 | Mario Beretta | 23 June 2008 | |
| Palermo | Stefano Colantuono[8] | Sacked | 4 September 2008 | Davide Ballardini | 4 September 2008 | |
| Bologna | Daniele Arrigoni[9] | Sacked | 3 November 2008 | Siniša Mihajlović | 3 November 2008 | |
| Chievo Verona | Giuseppe Iachini[10] | Sacked | 4 November 2008 | Domenico Di Carlo | 4 November 2008 | |
| Torino | Gianni De Biasi[11] | Sacked | 8 December 2008 | Walter Novellino | 8 December 2008 | |
| Reggina | Nevio Orlandi[12] | Sacked | 16 December 2008 | Giuseppe Pillon[13] | 16 December 2008 | |
| Reggina | Giuseppe Pillon[14] | Sacked | 25 January 2009 | Nevio Orlandi | 25 January 2009 | |
| Lecce | Mario Beretta[15] | Sacked | 9 March 2009 | Luigi De Canio[16] | 9 March 2009 | |
| Napoli | Edoardo Reja[17] | Sacked | 10 March 2009 | Roberto Donadoni | 10 March 2009 | |
| Torino | Walter Novellino[18] | Sacked | 24 March 2009 | Giancarlo Camolese | 24 March 2009 | |
| Bologna | Siniša Mihajlović[19] | Sacked | 14 April 2009 | Giuseppe Papadopulo | 14 April 2009 | |
| Juventus | Claudio Ranieri[20] | Sacked | 18 May 2009 | Ciro Ferrara[21] | 18 May 2009 |
Source: gazzetta.it
| Rank | Player | Club | Goals |
|---|---|---|---|
| 1 |  Zlatan Ibrahimović | Internazionale | 25 |
| 2 |  Diego Milito | Genoa | 24 |
| Marco Di Vaio | Bologna | ||
| 4 | Alberto Gilardino | Fiorentina | 19 |
| 5 |  Kaká | Milan | 16 |
| 6 | Alexandre Pato | Milan | 15 |
| 7 | Robert Acquafresca | Cagliari | 14 |
| Edinson Cavani | Palermo | ||
| Fabrizio Miccoli | Palermo | ||
| 10 | Alessandro Del Piero | Juventus | 13 |
| Filippo Inzaghi | Milan | ||
 Adrian Mutu | Fiorentina | ||
| Sergio Pellissier | Chievo | ||
| Fabio Quagliarella | Udinese | ||
| Francesco Totti | Roma | ||
| Mauro Zárate | Lazio |