Singles
2021 Open de Oeiras III
Champion	Carlos Alcaraz
Runner-up	Facundo Bagnis
Score	6–4, 6–4

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

Carlos Alcaraz won the title after defeating Facundo Bagnis 6–4, 6–4 in the final.

Seeds

Draw

Finals

	Semifinals							Final
		Taro Daniel	2	7	2
		Carlos Alcaraz	6	5	6
									Carlos Alcaraz	6	6
								7	Facundo Bagnis	4	4
	7	Facundo Bagnis	6	6
		Hugo Gaston	0	2

Top half

	First round							Second round							Quarterfinals							Semifinals
	1	J Veselý	6	77
	Q	H Grenier	4	62				1	J Veselý	3	3r
		S Ofner	1	64					H Dellien	6	4
		H Dellien	6	77												H Dellien	1	6	1
		B Rola	1	5												T Daniel	6	3	6
		T Daniel	6	7					T Daniel	6	6
		L Mayer	4	6	6				L Mayer	3	4
	6	JI Londero	6	1	4																		T Daniel	2	7	2
	3	F Coria	2	6	6																		C Alcaraz	6	5	6
	Q	A Molčan	6	4	1			3	F Coria	4	6	4
		M Cressy	63	4				WC	G Elias	6	4	6
	WC	G Elias	77	6											WC	G Elias	5	4
		C Alcaraz	6	6												C Alcaraz	7	6
		Y Uchiyama	0	3					C Alcaraz	3	6	6
		B Nakashima	6	6					B Nakashima	6	4	4
	5	Y Hanfmann	3	4

Bottom half

	First round							Second round							Quarterfinals							Semifinals
	7	F Bagnis	7	3
		C Taberner	5	2r				7	F Bagnis	2	6	6
		J Jung	6	4	3			Alt	F Ferreira Silva	6	4	2
	Alt	F Ferreira Silva	1	6	6										7	F Bagnis	6	5	7
	WC	N Borges	6	6											WC	N Borges	1	7	5
		B Zapata Miralles	4	4				WC	N Borges	6	6
	WC	J Domingues	4	2				4	P Martínez	2	4
	4	P Martínez	6	6																		7	F Bagnis	6	6
	8	P Sousa	3	77	4																		H Gaston	0	2
		D Džumhur	6	64	0r			8	P Sousa	6	6
		D Kudla	4	6	5				B van de Zandschulp	3	2
		B van de Zandschulp	6	3	7										8	P Sousa	3	6	2
		H Gaston	77	6												H Gaston	6	1	6
	Q	Z Bergs	61	1					H Gaston	6	6
	Q	E Gómez	77	3	6			Q	E Gómez	4	3
	2	S Johnson	64	6	3

References

External links

• Main draw
• Qualifying draw