The 2021 Biella Challenger Indoor was a professional tennis tournament played on hard courts. It was the 1st edition of the tournament which was part of the 2021 ATP Challenger Tour. It took place in Biella, Italy between 8 and 14 February 2021.
| Country | Player | Rank1 | Seed | |
|---|---|---|---|---|
 United Kingdom | Andy Murray | 124 | 1 | |
 Italy | Federico Gaio | 138 | 2 | |
 Egypt | Mohamed Safwat | 147 | 3 | |
| Italy | Lorenzo Giustino | 154 | 4 | |
 Slovakia | Martin Kližan | 156 | 5 | |
| Blaž Rola | 158 | 6 | ||
| Slovakia | Filip Horanský | 163 | 7 | |
 Kazakhstan | Dmitry Popko | 168 | 8 |
The following players received wildcards into the singles main draw:
The following players received entry from the qualifying draw:
Giovanni Fonio Fabrizio OrnagoSee main article: 2021 Biella Challenger Indoor – Singles.
Illya Marchenko def. Andy Murray 6–2, 6–4.See main article: 2021 Biella Challenger Indoor – Doubles.
Luis David Martínez / 
David Vega Hernández def. 
Szymon Walków / Jan Zieliński 6–4, 3–6, [10–8].