| Competition: | Serie A |
| Season: | 2004–05 |
| Dates: | 11 September 2004 – 29 May 2005 |
| Winners: | - |
| Relegated: | Bologna Brescia Atalanta |
| Continentalcup1: | Champions League |
| Continentalcup1 Qualifiers: | Juventus Milan Internazionale Udinese |
| Continentalcup2: | UEFA Cup |
| Continentalcup2 Qualifiers: | Sampdoria Palermo Roma |
| Continentalcup3: | Intertoto Cup |
| Continentalcup3 Qualifiers: | Lazio |
| League Topscorer: | Cristiano Lucarelli (24 goals) |
| Highest Scoring: | Parma 6–4 Livorno |
| Matches: | 380 |
| Total Goals: | 960 |
| Average Attendance: | 26,098 |
| Nextseason: | 2005–06 |
| Prevseason: | 2003–04 |
The 2004–05 Serie A (known as the Serie A TIM for sponsorship reasons) was the 103rd season of top-tier Italian football, the 73rd in a round-robin tournament. It was expanded to contain 20 clubs, which played 38 matches against each other, rather than the 34 matches in previous seasons, while relegations were reduced to three. The Coppa Campioni d'Italia was presented to the winners on the pitch for the first time.
The first two teams qualified directly to UEFA Champions League, teams ending in the third and fourth places had to play Champions League qualifications, teams ending in the fifth and sixth places qualified to UEFA Cup (another spot was given to the winner of Coppa Italia), while only the last three teams were to be relegated in Serie B, the Italian second division, following a regulations change.
Juventus finished as champions and Milan were runner-ups. Udinese qualified for the UEFA Champions League for the first time in its history. Palermo, in its first Serie A campaign in over 30 years, finished in sixth place, qualifying for the UEFA Cup for the first time in its history. Roma qualified for the UEFA Cup as the runners-up in the Coppa Italia because the cup winner, Internazionale, had already qualified for the Champions League.
Two teams, Brescia and Atalanta, were directly relegated to Serie B, while the third relegation place was to be decided among three teams (Fiorentina, Bologna and Parma), counting only the so-called classifica avulsa; that is, the table composed solely by the six matches among the three teams. Bologna and Parma had fewer points, and played the relegation tiebreaker. The tiebreaker was won by Parma, who were defeated 0–1 at home but won 0–2 away in the return match. This method of classifying teams on equal points totals was abolished for the 2005–06 season but returned for the 2022–23 season.
| Team | Head Coach | Kit manufacturer | Shirt sponsor | |
|---|---|---|---|---|
| Atalanta |  Delio Rossi | Asics | Promatech | |
| Bologna | Carlo Mazzone | Macron | Amica Chips | |
| Brescia | Alberto Cavasin | Kappa | Banca Lombarda e Piemontese | |
| Cagliari | Daniele Arrigoni | A-Line | Terra Sarda | |
| Chievo | Maurizio D'Angelo | Lotto | Paluani/Columbia TriStar Film Distributors International | |
| Fiorentina | Dino Zoff | Adidas | Toyota | |
| Internazionale | Roberto Mancini | Nike | Pirelli | |
| Juventus | Fabio Capello | Nike | Sky Sport/Tamoil (in UEFA matches) | |
| Lazio | Giuseppe Papadopulo | Puma | Parmacotto | |
| Lecce |  Zdeněk Zeman | Asics | Salento | |
| Livorno | Roberto Donadoni | Asics | Banca Carige | |
| Messina | Bortolo Mutti | Legea | Caffè Miscela d'Oro, Regione Siciliana/Air Malta | |
| Milan | Carlo Ancelotti | Adidas | Opel | |
| Parma | Pietro Carmignani | Champion | Champion | |
| Palermo | Francesco Guidolin | Lotto | Provincia di Palermo | |
| Reggina | Walter Mazzarri | Asics | Gicos, Stocco&Stocco | |
| Roma | Bruno Conti | Diadora | Mazda | |
| Sampdoria | Walter Novellino | Kappa | Erg | |
| Siena | Luigi De Canio | Lotto | Banca Monte dei Paschi di Siena | |
| Udinese | Luciano Spalletti | Le Coq Sportif | Kia Motors |
See also: Derby dell'Emilia. ----
