Singles
2021 Split Open
Final
Champion	Blaž Rola
Runner-up	Blaž Kavčič
Score	2–6, 6–3, 6–2
Events
Singles Doubles
← 2020 · Split Open · 2021 →

Francisco Cerúndolo was the defending champion^[1] but chose not to defend his title.

Blaž Rola won the title after defeating Blaž Kavčič 2–6, 6–3, 6–2 in the final.

	Semifinals							Final
	Alt	Kacper Żuk	6	3	2
	Q	Blaž Kavčič	2	6	6
								Q	Blaž Kavčič	6	3	2
								6	Blaž Rola	2	6	6
		Andrea Collarini	63	77	4
	6	Blaž Rola	77	63	6

	First round							Second round							Quarterfinals							Semifinals
	1	P Sousa	2r
	Alt	K Żuk	1					Alt	K Żuk	6	6
		J Clarke	61	0				WC	N Serdarušić	4	2
	WC	N Serdarušić	77	6											Alt	K Żuk	78	6
	Q	A Santillan	2	0r											PR	T Kokkinakis	66	3
	SE	Z Kolář	6	5				SE	Z Kolář	63	1
	PR	T Kokkinakis	3	6	6			PR	T Kokkinakis	77	6
	8	F Horanský	6	4	4																	Alt	K Żuk	6	3	2
	4	M Safwat	3	3																		Q	B Kavčič	2	6	6
	Q	B Kavčič	6	6				Q	B Kavčič	4	79	6
		E Ymer	6	6					E Ymer	6	67	4
		A Müller	0	4											Q	B Kavčič	4	6	6
		A Vukic	6	6												A Vukic	6	2	2
	WC	M Poljičak	1	1					A Vukic	2	6	6
		B Tomic	2	6	3			7	K Coppejans	6	4	4
	7	K Coppejans	6	4	6

	First round							Second round							Quarterfinals							Semifinals
	5	D Petrović	6	6
		L Rosol	1	3				5	D Petrović	6	6
		J Domingues	5	3					M Marterer	1	3
		M Marterer	7	6											5	D Petrović	2	3
		A Bolt	4	2												A Collarini	6	6
	Q	U Ignatik	6	6				Q	U Ignatik	6	2	1
		A Collarini	6	6					A Collarini	2	6	6
	3	S Ofner	4	4																			A Collarini	63	77	4
	6	B Rola	6	6																		6	B Rola	77	63	6
		D Popko	3	4				6	B Rola	6	7
	WC	D Ajduković	2	6	7			WC	D Ajduković	1	5
	PR	D Brown	6	4	5										6	B Rola	6	6
	Q	M Bašić	77	6											Q	M Bašić	2	4
		C İlkel	64	3				Q	M Bašić	77	6
		R Haase	6	4	77				R Haase	64	3
	2	M Polmans	3	6	64

• Main draw
• Qualifying draw