The 2021 Sardegna Open[1] was a tennis tournament on the 2021 ATP Tour. It was played on outdoor clay courts in Cagliari, Sardinia, Italy. It was organised with a single-year licence in 2021, and was held at Tennis Club Cagliari from April 5 to 11, 2021.[2]
The Italian 250 debuted October 2020 as a response to the COVID-19 pandemic to increase earning opportunities for players. It returned to Sardegna in 2021 and opened the red-clay season in Europe.[3]
See main article: 2021 Sardegna Open – Singles.
Lorenzo Sonego def. 
Laslo Đere, 2–6, 7–6(7–5), 6–4See main article: 2021 Sardegna Open – Doubles.
Lorenzo Sonego / Andrea Vavassori def. Simone Bolelli / 
Andrés Molteni, 6–3, 6–4| Event | W | F | SF | QF | Round of 16 | Round of 32 | width=85 | Q | width=85 | Q2 | width=85 | Q1 |
| Singles | 250 | 150 | 90 | 45 | 20 | 0 | 12 | 6 | 0 | |||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubles | 0 |
| Event | W | F | SF | QF | Round of 16 | Round of 32 | width=85 | Q2 | width=85 | Q1 |
| Singles | €40,100 | €28,750 | €20,465 | €13,650 | €8,770 | €5,275 | €2,580 | €1,340 | ||
| Doubles* | €14,970 | €10,730 | €7,060 | €4,590 | €2,690 |
| Country | Player | Rank1 | Seed |
|---|---|---|---|
 United Kingdom | Dan Evans | 29 | 1 |
| Taylor Fritz | 32 | 2 | |
| Italy | Lorenzo Sonego | 34 | 3 |
 Georgia | Nikoloz Basilashvili | 38 | 4 |
| Jan-Lennard Struff | 42 | 5 | |
 Australia | John Millman | 43 | 6 |
| Argentina | Guido Pella | 48 | 7 |
| Tommy Paul | 53 | 8 | |
The following players received wildcards into the main draw:
The following players received entry from the qualifying draw:
Jérémy Chardy → replaced by João Sousa Federico Coria
Aslan Karatsev → replaced by Lorenzo Musetti
Thiago Monteiro → replaced by 
Andrej Martin
Fernando Verdasco → replaced by Yannick Hanfmann| Country | Player | Country | Player | Rank1 | Seed | |
|---|---|---|---|---|---|---|
| Brazil | Marcelo Melo | Jean-Julien Rojer | 43 | 1 | ||
| Italy | Simone Bolelli | Argentina | Andrés Molteni | 133 | 2 | |
| Australia | Matthew Ebden |  India | Divij Sharan | 138 | 3 | |
| Jonny O'Mara | 165 | 4 |
The following pairs received wildcards into the doubles main draw:
The following pair received entry using a protected ranking:
Rajeev Ram / Joe Salisbury → replaced by 
Harri Heliövaara / 
Denys Molchanov Jonny O'Mara / Ken Skupski → replaced by Lloyd Glasspool / Jonny O'Mara