2021 Sparkassen ATP Challenger

{{Infobox tennis event|2021|Sparkassen ATP Challenger|

| date=8–14 November

| edition=12th

| location=Ortisei, Italy

| champs={{flagicon|GER}} Oscar Otte

| champd={{flagicon|CRO}} Antonio Šančić / {{flagicon|AUT}} Tristan-Samuel Weissborn

}}

The 2021 Sparkassen ATP Challenger was a professional tennis tournament played on indoor hard courts in Ortisei, Italy between 8 and 14 November 2021. It was the twelfth edition of the tournament and was part of the 2021 ATP Challenger Tour.

Singles main-draw entrants

class="sortable wikitable"
width="70"\| Country ! width="175"\| Player ! Rank¹ ! Seed
{{flag\|GER}} \|Oscar Otte \|126 \|1
{{flagu\|USA}} \|Maxime Cressy \|133 \|2
{{flag\|FRA}} \|Quentin Halys \|146 \|3
{{flag\|ECU}} \|Emilio Gómez \|149 \|4
{{flag\|ITA}} \|Federico Gaio \|151 \|5
{{flag\|ESP}} \|Fernando Verdasco \|165 \|6
{{flag\|SUI}} \|Marc-Andrea Hüsler \|186 \|7
{{flag\|ITA}} \|Alessandro Giannessi \|192 \|8

class="sortable wikitable"

width="70"| Country

! width="175"| Player

! Rank¹

! Seed

|126

|133

|146

|149

|151

|165

|186

|192

¹ Rankings are as of 1 November 2021.{{Cite web|url=http://www.atptour.com/en/rankings/singles|title=Rankings | Singles | ATP Tour | Tennis|website=ATP Tour}}

The following players received wildcards into the singles main draw:

The following players received entry from the qualifying draw:

{{flagicon|GER}} Oscar Otte def. {{flagicon|USA}} Maxime Cressy 7–6^(7–5), 6–4.

{{flagicon|CRO}} Antonio Šančić / {{flagicon|AUT}} Tristan-Samuel Weissborn def. {{flagicon|AUT}} Alexander Erler / {{flagicon|AUT}} Lucas Miedler 7–6^(10–8), 4–6, [10–8].