| Perrel – Singles | |
|---|---|
| 2018 Trofeo Faip–Perrel | |
| Champion |  Matteo Berrettini |
| Runner-up | Stefano Napolitano |
| Final score | 6–2, 3–6, 6–2 |
Jerzy Janowicz was the defending champion but chose not to defend his title.
Matteo Berrettini won the title after defeating Stefano Napolitano 6–2, 3–6, 6–2 in the final.
Matteo Berrettini (champion)
Gleb Sakharov (first round)
Jürgen Zopp (semifinals)
Mats Moraing (second round, retired) Lorenzo Sonego (semifinals)
Jaume Munar (first round) Salvatore Caruso (quarterfinals)
Uladzimir Ignatik (second round)| Semifinals | Final | ||||||||||||
| 1/SE | Matteo Berrettini | 6 | 65 | 6 | |||||||||
| 3 | Jürgen Zopp | 3 | 77 | 1 | |||||||||
| 1/SE | Matteo Berrettini | 6 | 3 | 6 | |||||||||
| Stefano Napolitano | 2 | 6 | 2 | ||||||||||
| 5 | Lorenzo Sonego | 3 | 62 | ||||||||||
| Stefano Napolitano | 6 | 77 | |||||||||||
| First round | Second round | Quarterfinals | Semifinals | ||||||||||||||||||||||||
| 1/SE | M Berrettini | 6 | 6 | ||||||||||||||||||||||||
| M Viola | 3 | 1 | 1/SE | M Berrettini | 6 | 64 | 7 | ||||||||||||||||||||
| N Kuhn | 61 | 4 | SE | C Lestienne | 4 | 77 | 5 | ||||||||||||||||||||
| SE | C Lestienne | 77 | 6 | 1/SE | M Berrettini | 79 | 7 | ||||||||||||||||||||
| V Millot | 6 | 6 | 7 | S Caruso | 67 | 5 | |||||||||||||||||||||
| Q |  N Serdarušić | 1 | 4 | V Millot | 0 | 2 | |||||||||||||||||||||
| Q | S Doumbia | 5 | 2 | 7 | S Caruso | 6 | 6 | ||||||||||||||||||||
| 7 | S Caruso | 7 | 6 | 1/SE | M Berrettini | 6 | 65 | 6 | |||||||||||||||||||
| 3 | J Zopp | 4 | 6 | 6 | 3 | J Zopp | 3 | 77 | 1 | ||||||||||||||||||
| B Zapata Miralles | 6 | 2 | 2 | 3 | J Zopp | 6 | 77 | ||||||||||||||||||||
| LL | L Vanni | 6 | 6 | LL | L Vanni | 3 | 63 | ||||||||||||||||||||
| P Martínez | 3 | 4 | 3 | J Zopp | 6 | 7 | |||||||||||||||||||||
 A Pavlásek | 6 | 6 | A Pavlásek | 4 | 5 | ||||||||||||||||||||||
 T Brkić | 4 | 1 | A Pavlásek | 6 | 7 | ||||||||||||||||||||||
| Q |  F Horanský | 3 | 0 | 8 | U Ignatik | 4 | 5 | ||||||||||||||||||||
| 8 | U Ignatik | 6 | 6 | ||||||||||||||||||||||||
| First round | Second round | Quarterfinals | Semifinals | ||||||||||||||||||||||||
| 5 | L Sonego | 4 | 6 | 6 | |||||||||||||||||||||||
 M Trungelliti | 6 | 3 | 2 | 5 | L Sonego | 6 | 6 | ||||||||||||||||||||
| A Šetkić | 3 | 62 | WC |  E Gulbis | 4 | 3 | |||||||||||||||||||||
| WC | E Gulbis | 6 | 77 | 5 | L Sonego | 6 | 66 | 6 | |||||||||||||||||||
 M Safwat | 7 | 3 | 6 | M Safwat | 3 | 78 | 2 | ||||||||||||||||||||
| B Bonzi | 5 | 6 | 2 | M Safwat | 6 | 0 | |||||||||||||||||||||
| Q |  L Grigelis | 2 | 3 | 4 | M Moraing | 3 | 0r | ||||||||||||||||||||
| 4 | M Moraing | 6 | 6 | 5 | L Sonego | 3 | 62 | ||||||||||||||||||||
| 6 | J Munar | 5 | 63 | S Napolitano | 6 | 77 | |||||||||||||||||||||
| S Napolitano | 7 | 77 | S Napolitano | 6 | 7 | ||||||||||||||||||||||
| WC | A Davidovich Fokina | 4 | 2 | WC |  T de Bakker | 3 | 5 | ||||||||||||||||||||
| WC | T de Bakker | 6 | 6 | S Napolitano | 69 | 6 | 6 | ||||||||||||||||||||
| WC | G Quinzi | 6 | 6 | A Arnaboldi | 711 | 2 | 1 | ||||||||||||||||||||
| LL | A Basso | 4 | 2 | WC | G Quinzi | 63 | 6 | 3 | |||||||||||||||||||
| A Arnaboldi | 77 | 7 | A Arnaboldi | 77 | 3 | 6 | |||||||||||||||||||||
| 2 | G Sakharov | 63 | 5 | ||||||||||||||||||||||||
Ivan Dodig was the defending champion but chose not to defend his title.
Stan Wawrinka was the defending champion and successfully defended his title, defeating Mischa Zverev in the final, 4–6, 6–3, 6–3.
Malek Jaziri was the defending champion and successfully defended his title.
Alexander Zverev was the defending champion, but chose not to participate this year.
Aljaž Bedene was the defending champion but chose not to defend his title.
Lucas Pouille was the defending champion, but lost in the second round to John Millman.
Roger Federer was the defending champion, but lost to Borna Ćorić in the final. This was Ćorić's first ATP 500 title. With Federer's loss, Rafael Nadal regained the world No. 1 ranking.
Novak Djokovic was the defending champion, but chose not to participate this year.
Matteo Berrettini was the defending champion but chose not to defend his title.
Oliver Marach and Philipp Oswald were the defending champions, but they chose to compete alongside different partners in Hamburg instead.
Rafael Nadal was the defending champion but withdrew with a knee injury before the tournament began.
Marco Cecchinato was the defending champion, but withdrew due to illness.
Alexander Zverev was the two-time defending champion, but lost to Cristian Garín in the quarterfinals.
Roger Federer was the defending champion, but chose not to participate this year.
Matteo Berrettini was the defending champion, but withdrew with an ankle injury before the tournament began.
Matteo Berrettini and Daniele Bracciali were the defending champions, but chose not to participate this year.
Nikoloz Basilashvili was the defending champion, but lost in the second round to Stefanos Tsitsipas.
Matteo Berrettini defeated Aslan Karatsev in the final, 6–1, 3–6, 7–6(7–0), to win the men's singles tennis title at the 2021 Serbia Open.
Feliciano López was the defending champion from when the event was last held in 2019, but lost in the second round to Denis Shapovalov.
Andrey Rublev was the defending champion, but chose to compete in St. Petersburg instead.