| Singles | |
|---|---|
| 2021 Tampere Open | |
| Champion |  Jiří Lehečka |
| Runner-up |  Nicolás Kicker |
| Score | 5–7, 6–4, 6–3 |
Mikael Ymer was the defending champion [1] but chose not to defend his title.
Jiří Lehečka won the title after defeating Nicolás Kicker 5–7, 6–4, 6–3 in the final.
Botic van de Zandschulp (semifinals)
Henri Laaksonen (withdrew)
Antoine Hoang (first round)
Mario Vilella Martínez (quarterfinals)
Dmitry Popko (quarterfinals)
Kimmer Coppejans (first round) Alexandre Müller (second round) Guido Andreozzi (second round)| Semifinals | Final | ||||||||||||
| 1 | Botic van de Zandschulp | 3 | 6 | 3 | |||||||||
| Q | Nicolás Kicker | 6 | 3 | 6 | |||||||||
| Q | Nicolás Kicker | 7 | 4 | 3 | |||||||||
| Jiří Lehečka | 5 | 6 | 6 | ||||||||||
| Jiří Lehečka | 6 | 6 | |||||||||||
| LL | Kyrian Jacquet | 3 | 0 | ||||||||||
| First round | Second round | Quarterfinals | Semifinals | ||||||||||||||||||||||||
| 1 | B van de Zandschulp | 4 | 6 | 6 | |||||||||||||||||||||||
 R Bonadio | 6 | 2 | 2 | 1 | B van de Zandschulp | 6 | 6 | ||||||||||||||||||||
 JC Aragone | 4 | 4 |  P Krstin | 3 | 1 | ||||||||||||||||||||||
| P Krstin | 6 | 6 | 1 | B van de Zandschulp | 6 | 77 | |||||||||||||||||||||
| A Arnaboldi | 6 | 6 | 5 | D Popko | 4 | 60 | |||||||||||||||||||||
 F Meligeni Alves | 1 | 4 | A Arnaboldi | 4 | 3 | ||||||||||||||||||||||
| Alt | O Luz | 65 | 5 | 5 | D Popko | 6 | 6 | ||||||||||||||||||||
| 5 | D Popko | 77 | 7 | 1 | B van de Zandschulp | 3 | 6 | 3 | |||||||||||||||||||
| 4/SE | M Vilella Martínez | 4 | 77 | 7 | Q | N Kicker | 6 | 3 | 6 | ||||||||||||||||||
 J Domingues | 6 | 65 | 5 | 4/SE | M Vilella Martínez | 7 | 6 | ||||||||||||||||||||
| Q |  B Bobrov | 1 | 5 | P Cachin | 5 | 4 | |||||||||||||||||||||
| P Cachin | 6 | 7 | 4/SE | M Vilella Martínez | 66 | 0 | |||||||||||||||||||||
| Q | N Kicker | 6 | 6 | Q | N Kicker | 78 | 6 | ||||||||||||||||||||
| WC |  Leo Borg | 3 | 0 | Q | N Kicker | 6 | 3 | 6 | |||||||||||||||||||
| WC |  P Niklas-Salminen | 2 | 1 | 7 | A Müller | 4 | 6 | 2 | |||||||||||||||||||
| 7 | A Müller | 6 | 6 | ||||||||||||||||||||||||
| First round | Second round | Quarterfinals | Semifinals | ||||||||||||||||||||||||
| 8 | G Andreozzi | 6 | 6 | ||||||||||||||||||||||||
 M Moraing | 4 | 1 | 8 | G Andreozzi | 2 | 4 | |||||||||||||||||||||
| Q | A Cazaux | 6 | 65 | 2 | WC | O Virtanen | 6 | 6 | |||||||||||||||||||
| WC | O Virtanen | 3 | 77 | 6 | WC | O Virtanen | 4 | 1 | |||||||||||||||||||
 N Jarry | 63 | 6 | 6 | J Lehečka | 6 | 6 | |||||||||||||||||||||
| Alt | J Forejtek | 77 | 3 | 3 | N Jarry | 4 | 4 | ||||||||||||||||||||
| J Lehečka | 6 | 6 | J Lehečka | 6 | 6 | ||||||||||||||||||||||
| 3 | A Hoang | 1 | 4 | J Lehečka | 6 | 6 | |||||||||||||||||||||
| 6 | K Coppejans | 6 | 3 | 66 | LL | K Jacquet | 3 | 0 | |||||||||||||||||||
 D Kuzmanov | 1 | 6 | 78 | D Kuzmanov | 6 | 4 | 65 | ||||||||||||||||||||
| LL | K Jacquet | 2 | 6 | 3 | LL | K Jacquet | 3 | 6 | 77 | ||||||||||||||||||
| G Oliveira | 6 | 1 | 0r | LL | K Jacquet | 6 | 6 | ||||||||||||||||||||
| Q | G Blancaneaux | 6 | 7 | Q | G Blancaneaux | 3 | 3 | ||||||||||||||||||||
| F Mena | 4 | 5 | Q | G Blancaneaux | 6 | 4 | 6 | ||||||||||||||||||||
| G Elias | 4 | 6 | 5 | LL |  A Erler | 3 | 6 | 2 | |||||||||||||||||||
| LL | A Erler | 6 | 3 | 7 | |||||||||||||||||||||||
Benjamin Bonzi and Quentin Halys were the defending champions, but were not eligible to compete this year.
Noah Rubin was the defending champion, but chose not to participate this year.
Lucas Miedler and Bradley Mousley were the defending champions but were no longer eligible to compete in juniors in 2015.
Marcel Granollers and David Marrero were the defending champions, but Granollers chose not to participate this year. Marrero played alongside Nenad Zimonjić, but lost in the quarterfinals to Elias and Mikael Ymer.
Noah Rubin was the defending champion but lost in the final to Mikael Ymer.
Reilly Opelka was the defending champion but chose not to defend his title.
Tallon Griekspoor was the defending champion but lost in the final to Mikael Ymer.
Aljaž Bedene was the defending champion but lost in the quarterfinals to Mikael Ymer.
Elias Ymer was the defending champion but chose not to defend his title.
Mikael Ymer was the defending champion but chose not to defend his title.
Roger Federer was the defending champion, but withdrew from the tournament after undergoing surgery on his right knee.
This was the third edition of the tournament, primarily created due to the one-week delay of the 2021 French Open.
Alex de Minaur defeated Lorenzo Sonego in the final, 4–6, 6–4, 7–6(7–5), to win the men's singles tennis title at the 2021 Eastbourne International. It was De Minaur's fifth career ATP Tour singles title and his first on grass. Sonego was contesting in his second grass final to win his third career title.
Mikael Ymer was the defending champion but chose not to defend his title.
Mikael Ymer was the defending champion but chose not to defend his title.
Andrey Rublev was the defending champion, but lost in the quarterfinals to Botic van de Zandschulp.
Ričardas Berankis was the defending champion but lost in the quarterfinals to Arthur Rinderknech.
Félix Auger-Aliassime defeated J. J. Wolf in the final, 6–4, 6–4 to win the singles tennis title at the 2022 Firenze Open. It was his second ATP Tour singles title.
Holger Rune defeated Stefanos Tsitsipas in the final, 6–4, 6–4 to win the singles tennis title at the 2022 Stockholm Open. It was his second career ATP Tour singles title.
Kwon Soon-woo defeated Roberto Bautista Agut in the final, 6–4, 3–6, 7–6(7–4) to win the men's singles tennis title at the 2023 Adelaide International 2. It was his second ATP Tour singles title, and he became just the tenth man in ATP Tour history to win a title as a lucky loser.