The 2005 Italian Grand Prix (officially the Formula 1 Gran Premio Vodafone d'Italia 2005) was a Formula One motor race held on 4 September 2005 at the Autodromo Nazionale di Monza, Italy. It was the fifteenth race of the 2005 FIA Formula One World Championship.

The 53-lap race was won from pole position by Colombia's Juan Pablo Montoya, driving a McLaren-Mercedes, his second victory with the team and penultimate in Formula One, with Renault drivers Fernando Alonso and Giancarlo Fisichella second and third respectively. Kimi Räikkönen was fourth, thus losing ground to Alonso at the top of the Drivers' Championship. Antônio Pizzonia scored his last world championship points at this race.

The bottom 6 teams in the 2004 Constructors' Championship were entitled to run a third car in free practice on Friday. These drivers drove on Friday but did not compete in qualifying or the race.

Constructor	Nat	Driver
McLaren-Mercedes		Pedro de la Rosa
Sauber-Petronas		-
Red Bull-Cosworth		Vitantonio Liuzzi
Toyota		Ricardo Zonta
Jordan-Toyota		Nicolas Kiesa
Minardi-Cosworth		Enrico Toccacelo

Fernando Alonso led the Drivers' Championship with 24 points ahead of Kimi Räikkönen and 40 points ahead of Michael Schumacher. In the constructors' championship, Renault led McLaren-Mercedes by nine points and Ferrari by 44 points.

Williams's Nick Heidfeld participated in Friday free practice sessions, but since he was suffering from headaches following an accident which occurred during the tests held on the circuit the previous week, he was replaced by Antônio Pizzonia starting from the first free practice on Saturday.

Kimi Räikkönen set the fastest time in qualifying in his McLaren-Mercedes, but received a 10-place grid penalty for changing his engine, demoting him to 11th on the grid and giving pole to teammate Juan Pablo Montoya.

Montoya led every lap, winning by 2.5 seconds from the Renault of Fernando Alonso, with Giancarlo Fisichella third in the other Renault. Räikkönen climbed through the field to finish fourth, ahead of Jarno Trulli, Ralf Schumacher, Antônio Pizzonia and Jenson Button. Räikkönen would have had a chance of winning with a one-stop strategy, but a deflated tyre forced him to make a second pit stop. Rubens Barrichello also had the same problem later in the day, and Montoya was lucky to finish in the lead, as his left rear tyre began to cut with several laps remaining.

Alonso extended his lead over Räikkönen in the Drivers' Championship to 27 points, 103 to 76, with Michael Schumacher third on 55 and Montoya fourth on 50. Mathematically, the championship was now a two-horse race between Alonso and Räikkönen. Renault retained an eight-point lead over McLaren-Mercedes in the Constructors' Championship, 144 to 136, Ferrari remaining in third on 86 and Toyota fourth on 78.

There were no retirements during the race, a feat that had not been achieved in Formula One with a full field since the 1961 Dutch Grand Prix, and would not be achieved again until the 2011 European Grand Prix. The 2005 United States Grand Prix is also considered to have had no retirements; however, only six cars started due to problems with the supply of Michelin tyres, which led to the mass withdrawal of all teams running on those tyres due to safety issues.

Pos	No	Driver	Constructor	Lap	Gap	Grid
1	9	Kimi Räikkönen	McLaren-Mercedes	1:20.878	—	11
2	10	Juan Pablo Montoya	McLaren-Mercedes	1:21.054	+0.176	1
3	5	Fernando Alonso	Renault	1:21.319	+0.441	2
4	3	Jenson Button	BAR-Honda	1:21.369	+0.491	3
5	4	Takuma Sato	BAR-Honda	1:21.477	+0.599	4
6	16	Jarno Trulli	Toyota	1:21.640	+0.762	5
7	1	Michael Schumacher	Ferrari	1:21.721	+0.843	6
8	2	Rubens Barrichello	Ferrari	1:21.962	+1.084	7
9	6	Giancarlo Fisichella	Renault	1:22.068	+1.190	8
10	17	Ralf Schumacher	Toyota	1:22.266	+1.388	9
11	14	David Coulthard	Red Bull-Cosworth	1:22.304	+1.426	10
12	11	Jacques Villeneuve	Sauber-Petronas	1:22.356	+1.478	12
13	15	Christian Klien	Red Bull-Cosworth	1:22.532	+1.654	13
14	7	Mark Webber	Williams-BMW	1:22.560	+1.682	14
15	12	Felipe Massa	Sauber-Petronas	1:23.060	+2.182	15
16	8	Antônio Pizzonia	Williams-BMW	1:23.291	+2.413	16
17	18	Tiago Monteiro	Jordan-Toyota	1:24.666	+3.788	17
18	20	Robert Doornbos	Minardi-Cosworth	1:24.904	+4.026	18
19	19	Narain Karthikeyan	Jordan-Toyota	1:25.859	+4.981	19
20	21	Christijan Albers	Minardi-Cosworth	1:26.964	+6.086	20
Source:

Notes

• ^1 – Kimi Räikkönen received a 10-place grid penalty for an engine change.

Pos	No	Driver	Constructor	Tyre	Laps	Time/Retired	Grid	Points
1	10	Juan Pablo Montoya	McLaren-Mercedes	M	53	1:14:28.659	1	10
2	5	Fernando Alonso	Renault	M	53	+ 2.479	2	8
3	6	Giancarlo Fisichella	Renault	M	53	+ 17.975	8	6
4	9	Kimi Räikkönen	McLaren-Mercedes	M	53	+ 22.775	11	5
5	16	Jarno Trulli	Toyota	M	53	+ 33.786	5	4
6	17	Ralf Schumacher	Toyota	M	53	+ 43.925	9	3
7	8	Antônio Pizzonia	Williams-BMW	M	53	+ 44.643	16	2
8	3	Jenson Button	BAR-Honda	M	53	+ 1:03.635	3	1
9	12	Felipe Massa	Sauber-Petronas	M	53	+ 1:15.413	15
10	1	Michael Schumacher	Ferrari	B	53	+ 1:36.070	6
11	11	Jacques Villeneuve	Sauber-Petronas	M	52	+ 1 Lap	12
12	2	Rubens Barrichello	Ferrari	B	52	+ 1 Lap	7
13	15	Christian Klien	Red Bull-Cosworth	M	52	+ 1 Lap	13
14	7	Mark Webber	Williams-BMW	M	52	+ 1 Lap	14
15	14	David Coulthard	Red Bull-Cosworth	M	52	+ 1 Lap	10
16	4	Takuma Sato	BAR-Honda	M	52	+ 1 Lap	4
17	18	Tiago Monteiro	Jordan-Toyota	B	51	+ 2 Laps	17
18	20	Robert Doornbos	Minardi-Cosworth	B	51	+ 2 Laps	18
19	21	Christijan Albers	Minardi-Cosworth	B	51	+ 2 Laps	20
20	19	Narain Karthikeyan	Jordan-Toyota	B	50	+ 3 Laps	19
Sources:

• Bold text and an asterisk indicates who still has a theoretical chance of becoming World Champion.

• Note: Only the top five positions are included for both sets of standings.

• 2005 Monza GP2 Series round

Previous race: 2005 Turkish Grand Prix	FIA Formula One World Championship 2005 season	Next race: 2005 Belgian Grand Prix
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