The 1999 Grand Prix of Sonoma was the fourth round of the 1999 American Le Mans Series season. It took place at Sears Point Raceway, California, on July 25, 1999.

Class winners in bold.

Pos	Class	No	Team	Drivers	Chassis	Tyre	Laps
					Engine
1	LMP	42	BMW Motorsport Schnitzer Motorsport	JJ Lehto Steve Soper	BMW V12 LMR	M	97
					BMW S70 6.0 L V12
2	LMP	1	Panoz Motor Sports	David Brabham Éric Bernard	Panoz LMP-1 Roadster-S	M	97
					Ford (Élan-Yates) 6.0 L V8
3	LMP	2	Panoz Motor Sports	Johnny O'Connell Jan Magnussen	Panoz LMP-1 Roadster-S	M	96
					Ford (Élan-Yates) 6.0 L V8
4	LMP	20	Dyson Racing	Butch Leitzinger Elliott Forbes-Robinson	Riley & Scott Mk III	G	96
					Ford 5.0 L V8
5	LMP	43	BMW Motorsport Schnitzer Motorsport	Joachim Winkelhock Bill Auberlen	BMW V12 LMR	M	96
					BMW S70 6.0 L V12
6	LMP	0	Team Rafanelli SRL	Érik Comas Mimmo Schiattarella	Riley & Scott Mk III	Y	96
					Judd GV4 4.0 L V10
7	LMP	27	Price & Bscher	Thomas Bscher Pedro Lamy	BMW V12 LM	Y	95
					BMW S70 6.0 L V12
8	LMP	36	Doran Lista Racing Jim Matthews Racing	Stefan Johansson Jim Matthews	Ferrari 333 SP	M	94
					Ferrari F310E 4.0 L V12
9	LMP	27	Doran Lista Racing	Didier Theys Fredy Lienhard	Ferrari 333 SP	M	94
					Ferrari F310E 4.0 L V12
10	LMP	11	Doyle-Risi Racing	Max Angelelli Didier de Radiguès	Ferrari 333 SP	P	94
					Ferrari F310E 4.0 L V12
11	LMP	74	Robinson Racing	George Robinson Jack Baldwin	Riley & Scott Mk III	?	93
					Chevrolet 6.0 L V8
12	LMP	38	Champion Racing	Allan McNish Andy Pilgrim	Porsche 911 GT1 Evo	M	93
					Porsche 3.2 L Turbo Flat-6
13	LMP	16	Dyson Racing	Rob Dyson James Weaver	Riley & Scott Mk III	G	93
					Ford 5.0 L V8
14	LMP	18	Dollahite Racing	Bill Dollahite Mike Davies	Ferrari 333 SP	P	92
					Ferrari F310E 4.0 L V12
15	LMP	15	Hybrid R&D	Chris Bingham Ross Bentley	Riley & Scott Mk III	Y	92
					Ford 5.0 L V8
16	LMP	8	Transatlantic Racing	Scott Schubot Rick Sutherland	Riley & Scott Mk III	G	90
					Ford 5.0 L V8
17	GTS	91	Dodge Viper Team Oreca	Olivier Beretta David Donohue	Dodge Viper GTS-R	M	90
					Dodge 8.0 L V10
18	GTS	3	Corvette Racing	Chris Kneifel Ron Fellows	Chevrolet Corvette C5-R	G	89
					Chevrolet 6.0 L V8
19	GTS	92	Dodge Viper Team Oreca	Karl Wendlinger Tommy Archer	Dodge Viper GTS-R	M	89
					Dodge 8.0 L V10
20	GTS	55	Saleen/Allen Speedlab	Terry Borcheller Ron Johnson	Saleen Mustang SR	P	88
					Ford 8.0 L V8
21	GTS	56	Martin Snow Racing	Martin Snow Kelly Collins	Porsche 911 GT2	M	88
					Porsche 3.6 L Turbo Flat-6
22	GT	9	Prototype Technology Group	Boris Said Hans-Joachim Stuck	BMW M3	Y	88
					BMW 3.2 L I6
23	GT	23	Manthey Racing Alex Job Racing	Dirk Müller Cort Wagner	Porsche 911 GT3-R	M	88
					Porsche 3.6 L Flat-6
24	GTS	48	Freisinger Motorsport	Wolfgang Kaufmann Michel Ligonnet	Porsche 911 GT2	D	87
					Porsche 3.6 L Turbo Flat-6
25	GTS	61	Konrad Motorsport	Franz Konrad Bob Wollek	Porsche 911 GT2	D	87
					Porsche 3.6 L Turbo Flat-6
26	GT	10	Prototype Technology Group	Darren Law Johannes van Overbeek	BMW M3	Y	87
					BMW 3.2 L I6
27	GT	22	Alex Job Racing	Mike Fitzgerald Darryl Havens	Porsche 911 Carrera RSR	Y	86
					Porsche 3.8 L Flat-6
28	GT	24	Alex Job Racing	Randy Pobst Jim Kelly	Porsche 911 Carrera RSR	Y	86
					Porsche 3.8 L Flat-6
29	GT	02	Reiser Callas Rennsport	Doc Bundy David Murry	Porsche 911 Carrera RSR	P	86
					Porsche 3.8 L Flat-6
30	GT	68	The Racer's Group	Kevin Buckler Vic Rice	Porsche 911 Carrera RSR	G	85
					Porsche 3.8 L Flat-6
31	GT	03	Reiser Callas Rennsport	Grady Willingham Joel Reiser Craig Stanton	Porsche 911 Carrera RSR	P	85
					Porsche 3.8 L Flat-6
32	GT	25	RWS Motorsport	Hans-Jörg Hofer Luca Riccitelli	Porsche 911 GT3-R	M	84
					Porsche 3.6 L Flat-6
33	GTS	83	Chiefie Motorsports	Stefano Buttiero Zak Brown	Porsche 911 GT2	?	83
					Porsche 3.6 L Turbo Flat-6
34	GT	67	The Racer's Group	Michael Schrom Spencer Trenery	Porsche 911 Carrera RSR	G	83
					Porsche 3.8 L Flat-6
35	GT	88	Vanderhoof Racing	Joe Varde Tim Ralston	Porsche 911 Carrera RSR	?	82
					Porsche 3.8 L Flat-6
36 DNF	GT	6	Prototype Technology Group	Peter Cunningham Mark Simo	BMW M3	Y	79
					BMW 3.2 L I6
37	GT	17	Contemporary Motorsports	Mike Conte Bruno Lambert	Porsche 911 Carrera RSR	?	78
					Porsche 3.8 L Flat-6
38 DNF	LMP	12	Doyle-Risi Racing	Alex Caffi Wayne Taylor	Ferrari 333 SP	P	73
					Ferrari F310E 4.0 L V12
39	LMP	63	Downing Atlanta	Jim Downing Chris Ronson	Kudzu DLY	G	63
					Mazda R26B 2.6 L 4-Rotor
40 DNF	LMP	28	Intersport Racing	Jon Field Niclas Jönsson	Lola B98/10	G	38
					Ford (Roush) 6.0 L V8
41 DNF	GT	76	Team ARE	Harry Rady Simon Sobrero	Porsche 911 Carrera RSR	Y	36
					Porsche 3.8 L Flat-6
42 DNF	GT	7	Prototype Technology Group	Brian Cunningham Christian Menzel	BMW M3	Y	2
					BMW 3.2 L I6
DNQ	LMP	97	Team Cascadia	Ed Zabinski Shane Lewis	Lola B98/10	P	-
					Chevrolet 6.0 L V8
DNQ	LMP	29	Intersport Racing	Sam Brown Steve Romak John Mirro	Riley & Scott Mk III	G	-
					Ford (Roush) 6.0 L V8
DNQ	LMP	60	Kopf Precision Products	Kris Wilson Tim Moser	Keiler KII	?	-
					Ford 5.0 L V8

• Pole Position - #42 BMW Motorsport (J.J. Lehto) - 1:22.387
• Fastest Lap - #42 BMW Motorsport (J.J. Lehto) - 1:23.835
• Distance - 393.388 km (244.440 mi)
• Average Speed - 143.890 km/h (89.409 mph)

• "Official Results" (PDF). International Motor Sports Association. 1999. Archived from the original (PDF) on October 16, 2005. Retrieved November 2, 2007.
• "American Le Mans Series 1999". World Sports Racing Prototypes. Archived from the original on September 19, 2008.