Singles
2021 Estoril Open
Final
Champion	Albert Ramos Viñolas
Runner-up	Cameron Norrie
Score	4–6, 6–3, 7–6(7–3)
Details
Draw	28 (4 Q / 3 WC )
Seeds	8
Events
Singles Doubles
← 2019 · Estoril Open · 2022 →

Albert Ramos Viñolas defeated Cameron Norrie in the final, 4–6, 6–3, 7–6^(7–3) to win the singles tennis title at the 2021 Estoril Open. It marked his third career ATP Tour singles title, all of which have been on clay. Norrie was aiming to win his first ATP Tour title in his second final.^[1]

Stefanos Tsitsipas was the defending champion from when the tournament was last held in 2019,^[2] but did not return to compete.

The top four seeds received a bye into the second round.

	Semifinals							Final
	7	Albert Ramos Viñolas	6	6
	8	Alejandro Davidovich Fokina	1	4
								7	Albert Ramos Viñolas	4	6	77
									Cameron Norrie	6	3	63
	6	Marin Čilić	65	5
		Cameron Norrie	77	7

	First round							Second round							Quarterfinals							Semifinals
								1/WC	D Shapovalov	4	6	4
		M Giron	4	79	4				C Moutet	6	2	6
		C Moutet	6	67	6											C Moutet	4	3
		G Simon	5	3											7	A Ramos Viñolas	6	6
		P-H Herbert	7	6					P-H Herbert	2	63
		F Verdasco	3	3				7	A Ramos Viñolas	6	77
	7	A Ramos Viñolas	6	6																		7	A Ramos Viñolas	6	6
																						8	A Davidovich Fokina	1	4
								3	U Humbert	6	3	6
		M Cecchinato	6	6					M Cecchinato	4	6	3
		L Harris	3	4											3	U Humbert	4	4
		J Chardy	3	6	6										8	A Davidovich Fokina	6	6
	Q	J Munar	6	3	4				J Chardy	1	2
		P Andújar	3	6	1			8	A Davidovich Fokina	6	6
	8	A Davidovich Fokina	6	4	6

	First round							Second round							Quarterfinals							Semifinals
	6	M Čilić	6	1	6
	Q	C Alcaraz	3	6	4			6	M Čilić	65	6	6
	Q	N Borges	77	6				Q	N Borges	77	4	4
		J Thompson	65	3											6	M Čilić	79	0
		K Anderson	4	78	77											K Anderson	67	0r
		F Tiafoe	6	66	64				K Anderson	6	77
								LL	R Carballés Baena	3	64
																						6	M Čilić	65	5
	5	A Bublik	3	0																			C Norrie	77	7
	Q	P Martínez	6	6				Q	P Martínez	6	61	5
		C Norrie	6	6					C Norrie	4	77	7
	WC	J Sousa	1	3												C Norrie	3	7	6
		JI Londero	3	5											2	C Garín	6	5	3
		R Gasquet	6	7					R Gasquet
								2	C Garín	w/o

	First round							Qualifying competition
	1	Jaume Munar	6	77
		Thomas Fabbiano	4	65
								1	Jaume Munar	78	6
								WC	Frederico Ferreira Silva	66	3
	WC	Frederico Ferreira Silva	6	6
	7	Brandon Nakashima	2	3

	First round							Qualifying competition
	2	Roberto Carballés Baena	7	7
		Henri Laaksonen	5	5
								2	Roberto Carballés Baena	5	4
								WC	Nuno Borges	7	6
	WC	Nuno Borges	6	7
	8	Liam Broady	3	5

	First round							Qualifying competition
	Alt	João Domingues	4	2
		Carlos Taberner	6	6
									Carlos Taberner	5	3
								6	Carlos Alcaraz	7	6
		Tallon Griekspoor	1	3
	6	Carlos Alcaraz	6	6

	First round							Qualifying competition
	4	Pedro Martínez	6	64	6
		Botic van de Zandschulp	4	77	1
								4	Pedro Martínez	7	7
									Marc-Andrea Hüsler	5	5
		Marc-Andrea Hüsler	6	6
	5	Pedro Sousa	2	4

• Main draw
• Qualifying draw