2021 Challenger de Santiago

Country	Player	Rank1	Seed
ESP	Roberto Carballés Baena	97	1
SVK	Andrej Martin	104	2
POR	Pedro Sousa	110	3
ARG	Facundo Bagnis	118	4
SVK	Jozef Kovalík	129	5
GER	Daniel Altmaier	143	6
BEL	Kimmer Coppejans	165	7
CHI	Alejandro Tabilo	168	8

• ¹ Rankings are as of 8 March 2021.^[1]

The following players received wildcards into the singles main draw:

• Nicolás Jarry
• Gonzalo Lama
• Holger Rune

The following player received entry into the singles main draw as an alternate:

• Camilo Ugo Carabelli

The following players received entry from the qualifying draw:

• Martín Cuevas
• Nicolás Kicker
• João Menezes
• Gonzalo Villanueva

The following player received entry as a lucky loser:

• Rafael Matos

• Sebastián Báez def. Marcelo Tomás Barrios Vera 6–3, 7–6^(7–4).

• Luis David Martínez / Gonçalo Oliveira def. Rafael Matos / Felipe Meligeni Alves 7–5, 6–1.