Singles
2021 Saint Petersburg Challenger II
Final
Champion	Evgenii Tiurnev
Runner-up	Kacper Żuk
Score	6–4, 6–2
Events
Singles Doubles
← 2021 · Saint Petersburg Challenger · 2022 →

Zizou Bergs was the defending champion^[1] but lost in the second round to Kacper Żuk.

Evgenii Tiurnev won the title after defeating Żuk 6–4, 6–2 in the final.

	Semifinals							Final
	WC	Evgenii Tiurnev	77	6
	4	Marius Copil	64	2
								WC	Evgenii Tiurnev	6	6
								6	Kacper Żuk	4	2
	6	Kacper Żuk	79	6
	Q	Jiří Lehečka	67	3

	First round							Second round							Quarterfinals							Semifinals
	1	R Safiullin	4	67
	Q	M Bašić	6	79				Q	M Bašić	6	77
		R Ortega Olmedo	6	6					R Ortega Olmedo	1	63
		R Quiroz	3	3											Q	M Bašić	4	2
		V Kopřiva	4	2											WC	E Tiurnev	6	6
	WC	E Tiurnev	6	6				WC	E Tiurnev	6	2	6
		A Çelikbilek	6	6					A Çelikbilek	3	6	3
	8	T Gabashvili	2	2																		WC	E Tiurnev	77	6
	4	M Copil	6	6																		4	M Copil	64	2
	Alt	M Vrbenský	3	1				4	M Copil	5	6	6
		D-h Lee	6	1	1				A Vatutin	7	3	1
		A Vatutin	0	6	6										4	M Copil	77	7
		D Ajduković	7	6											7	C Eubanks	61	5
		Shuichi Sekiguchi	5	2					D Ajduković	3	3
	Alt	J de Jong	5	4				7	C Eubanks	6	6
	7	C Eubanks	7	6

	First round							Second round							Quarterfinals							Semifinals
	6	K Żuk	6	6
		I Sijsling	4	3				6	K Żuk	1	6	6
	SE	Z Bergs	6	6				SE	Z Bergs	6	4	3
		P Krstin	2	1											6	K Żuk	6	6
		P Kotov	6	6												J Sock	3	2
	Q	T van Rijthoven	2	4					P Kotov	4	3
		J Sock	5	6	6				J Sock	6	6
	3	C İlkel	7	4	4																	6	K Żuk	79	6
	5	R Molleker	6	7																		Q	J Lehečka	67	3
		E Karlovskiy	3	5				5	R Molleker	2	3
	Q	J Lehečka	6	77				Q	J Lehečka	6	6
	Q	M Pecotić	2	64											Q	J Lehečka	6	6
	WC	D Yevseyev	6	6											2	D Popko	4	4
	WC	V Uzakov	0	0				WC	D Yevseyev	4	6	4
		N Serdarušić	4	4				2	D Popko	6	2	6
	2	D Popko	6	6

• Main draw
• Qualifying draw