Jim Courier defeated Guy Forget in the final, 4–6, 6–3, 4–6, 6–3, 7–6^(7–4) to win the men's singles tennis title at the 1991 Indian Wells Masters.

Stefan Edberg was the defending champion, but lost to Forget in the semifinals.

The top eight seeds receive a bye into the second round.

	Quarterfinals							Semifinals							Final
	1	Stefan Edberg	1	6	7
	9	Michael Chang	6	2	5
								1	Stefan Edberg	4	4
								3	Guy Forget	6	6
	3	Guy Forget	7	6
		Scott Davis	5	1
															3	Guy Forget	6	3	6	3	64
															16	Jim Courier	4	6	4	6	77
	11	Michael Stich	6	2	6
		Richey Reneberg	0	6	4
								11	Michael Stich	3	2
								16	Jim Courier	6	6
	7	Emilio Sánchez	2	2
	16	Jim Courier	6	6

	First round							Second round							Third round							Quarterfinals
								1	S Edberg	6	6
		M Jaite	7	5	6				M Jaite	3	2
		D Wheaton	5	7	4										1	S Edberg	3	7	6
		D Cahill	6	6												D Cahill	6	5	2
		V Paloheimo	3	4					D Cahill	77	6
	Q	S Bryan	6	6				Q	S Bryan	61	2
	15	J Aguilera	3	1																		1	S Edberg	1	6	7
	9	M Chang	6	6																		9	M Chang	6	2	5
		M Filippini	1	1				9	M Chang	6	4	6
		H Leconte	66	3					J Arias	4	6	1
		J Arias	78	6											9	M Chang	6	3	6
		J Fleurian	4	4											Q	W Ferreira	3	6	4
	Q	W Ferreira	6	6				Q	W Ferreira	6	77
								8	Gómez	4	65

	First round							Second round							Third round							Quarterfinals
								3	G Forget	6	6
		T Carbonell	6	6					T Carbonell	1	3
		G Muller	4	1											3	G Forget	6	6
	Q	D Goldie	4	5												D Rostagno	3	1
		D Rostagno	6	7					D Rostagno	7	6
		P Lundgren	68	4				14	M Rosset	5	1
	14	M Rosset	710	6																		3	G Forget	7	6
	12	J McEnroe	77	2	7																		S Davis	5	1
		W Masur	65	6	5			12	J McEnroe	67	5
		J Grabb	77	2	6				J Grabb	79	7
		G Bloom	65	6	1											J Grabb	4	4
		S Davis	77	7												S Davis	6	6
		J Sánchez	65	5					S Davis	6	6
								6	T Muster	3	2

	First round							Second round							Third round							Quarterfinals
								5	G Ivanišević	0	2
		A Rahunen	1	4					F Santoro	6	6
		F Santoro	6	6												F Santoro	6	3	4
	WC	G Layendecker	4	6	6										11	M Stich	4	6	6
	Q	K Jones	6	3	3			WC	G Layendecker	3	63
		T Mayotte	3	1				11	M Stich	6	77
	11	M Stich	6	6																		11	M Stich	6	2	6
	13	A Volkov	65	6	6																		R Reneberg	0	6	4
		T Champion	77	3	4			13	A Volkov	77	2	4
		K Curren	77	67	66				R Reneberg	64	6	6
		R Reneberg	62	79	78											R Reneberg	2	6	6
	WC	C Caratti	1	7	62										LL	F Clavet	6	3	0
	Q	R Furlan	6	5	77			Q	R Furlan	0	79	2
								LL	F Clavet	6	67	6

	First round							Second round							Third round							Quarterfinals
								7	E Sánchez	6	6
		S Bruguera	7	7					S Bruguera	4	4
		T Witsken	5	5											7	E Sánchez	6	77
	Q	B Pearce	4	2											10	A Cherkasov	3	62
		L Mattar	6	6					L Mattar	5	77	4
		P Korda	5	1				10	A Cherkasov	7	65	6
	10	A Cherkasov	7	6																		7	E Sánchez	2	2
	16	J Courier	6	3	6																	16	J Courier	6	6
	WC	G Raoux	4	6	2			16	J Courier	6	77
		M Vajda	1	6	3				B Black	1	64
	WC	B Black	6	3	6										16	J Courier	2	6	6
	Q	M Ruah	3	1											2	A Agassi	6	3	4
		G Prpić	6	6					G Prpić	3	4
								2	A Agassi	6	6

• Singles Draw