Johan Kriek defeated Steve Denton in the final, 6–2, 7–6^(7–1), 6–7^(1–7), 6–4 to win the men's singles tennis title at the 1981 Australian Open. It was his first major title, becoming the first South African to win a singles major. Kriek was making his tournament debut.

Brian Teacher was the reigning champion, but did not compete this year.

The seeded players are listed below. Johan Kriek is the champion; others show the round in which they were eliminated.

• Q = Qualifier
• WC = Wild card
• LL = Lucky loser
• r = Retired

	Quarterfinals									Semifinals									Final
	12	Hank Pfister	6	4	6	6
	5	Kim Warwick	1	6	4	3
										12	Hank Pfister	6	7	1	6	3
											Steve Denton	7	6	6	3	6
	9	Shlomo Glickstein	4	6	6	0
		Steve Denton	6	3	7	6
																				Steve Denton	2	6	7	4
																			4	Johan Kriek	6	7	6	6
	8	Tim Mayotte	6	3	5
	4	Johan Kriek	7	6	7
										4	Johan Kriek	6	7	7
										6	Mark Edmondson	0	6	5
	6	Mark Edmondson	7	7	6
	2	Peter McNamara	5	6	3

	First round									Second round									Third round									Quarterfinals
	1	G Vilas	6	6	7
		J Nyström	4	2	6					1	G Vilas	6	6	6	6
	Q	W Masur	6	4	6	2	6				L Stefanki	7	3	4	4
		L Stefanki	4	6	2	6	7												1	G Vilas	3	4	4
		H Simonsson	6	7	6	6													12	H Pfister	6	6	6
		R Hightower	4	6	7	3					H Simonsson	2	0	2
		L Bourne	6	6	3	6	1			12	H Pfister	6	6	6
	12	H Pfister	3	7	6	2	6																					12	H Pfister	6	4	6	6
	16	J Fitzgerald	7	6	6	3	4																					5	K Warwick	1	6	4	3
		P Dent	5	3	7	6	6				P Dent	7	6	7
		C Fancutt	3	6	6	6					C Fancutt	6	4	6
		C Johnstone	6	4	3	0														P Dent	3	3	0
		J Gurfein	6	7	6														5	K Warwick	6	6	6
	Q	W Pascoe	3	6	3						J Gurfein	5	2	5
		B Drewett	4	1	2					5	K Warwick	7	6	7
	5	K Warwick	6	6	6

	First round									Second round									Third round									Quarterfinals
	3	R Tanner	6	6	6
		G Whitecross	3	3	3					3	R Tanner	3	6	4	3
		R Frawley	2	6	6	3	6				R Frawley	6	4	6	6
		A Järryd	6	2	1	6	3													R Frawley	2	3	2
		D Siegler	6	6	3	3	3												9	S Glickstein	6	6	6
		J Potier	3	1	6	6	6				J Potier	3	4	2
		C Dunk	4	6	5					9	S Glickstein	6	6	6
	9	S Glickstein	6	7	7																							9	S Glickstein	4	6	6	0
	14	K Curren	6	6	6																								S Denton	6	3	7	6
		S Krulevitz	2	2	1					14	K Curren	7	6	3	2	2
		E Edwards	6	7	3	6	3				S Denton	6	3	6	6	6
		S Denton	7	6	6	4	6													S Denton	6	4	7	7	7
		T Tulasne	6	6	7															J Alexander	7	6	6	5	6
		O Parun	3	4	5						T Tulasne	4	1	3
		J Alexander	2	6	3	6	7				J Alexander	6	6	6
	7	F Buehning	6	4	6	1	6

	First round									Second round									Third round									Quarterfinals
	8	T Mayotte	6	6	6
	Q	E Sherbeck	2	3	1					8	T Mayotte	7	6	6
		R Van't Hof	6	6	1	4	6				R Van't Hof	6	3	3
		T Wilkison	3	3	6	6	3												8	T Mayotte	7	7	6
		R Simpson	6	7	6	6	6												13	P DuPré	6	5	4
	Q	D Collings	7	5	7	4	4				R Simpson	4	4	2
		B Guan	4	7	6	3	3			13	P DuPré	6	6	6
	13	P DuPré	6	6	4	6	6																					8	T Mayotte	6	3	5
	11	C Lewis	6	6	6																							4	J Kriek	7	6	7
		I Năstase	4	3	2					11	C Lewis	6	6	6
		J Smith	2	6	7	4	1				M Davis	4	3	3
		M Davis	6	7	6	6	6												11	C Lewis	5	5	6	6	4
	Q	T Högstedt	7	6	6														4	J Kriek	7	7	3	2	6
		S McCain	5	4	2					Q	T Högstedt	2	4	6
	Q	D Gitlin	2	5	1					4	J Kriek	6	6	7
	4	J Kriek	6	7	6

	First round									Second round									Third round									Quarterfinals
	6	M Edmondson	6	6	6
		P Cash	1	2	3					6	M Edmondson	5	1	7	7	6
		S Ball	6	6	4	7					S Ball	7	6	5	5	4
	Q	S Meister	2	4	6	6													6	M Edmondson	6	6	6
		J Delaney	6	3	6	7													Q	C Letcher	2	0	3
	Q	M Mitchell	4	6	3	6					J Delaney	6	6	6	6	4
	Q	C Letcher	3	6	6	6				Q	C Letcher	7	7	4	3	6
	10	J Sadri	6	3	4	4																						6	M Edmondson	7	7	6
	15	P Rennert	6	6	3	6																						2	P McNamara	5	6	3
		CA Miller	2	2	6	3				15	P Rennert	6	1	3
		P Kronk	3	6	6	7					P Kronk	7	6	6
		M Wilander	6	3	4	5														P Kronk	6	2	2	6	3
		R Lewis	7	6	6														2	P McNamara	1	6	6	4	6
		C Wittus	6	4	0						R Lewis	6	6	5	4	2
		D Carter	0	2	2					2	P McNamara	3	4	7	6	6
	2	P McNamara	6	6	6

• Association of Tennis Professionals (ATP) – 1981 Australian Open Men's Singles draw
• 1981 Australian Open – Men's draws and results at the International Tennis Federation