| Singles | |
|---|---|
| 2017 Sibiu Open | |
| Champion |  Cedrik-Marcel Stebe |
| Runner-up |  Carlos Taberner |
| Final score | 6–3, 6–3 |
Robin Haase was the defending champion but chose not to defend his title.
Cedrik-Marcel Stebe won the title after defeating Carlos Taberner 6–3, 6–3 in the final.
Cedrik-Marcel Stebe (champion)
Laslo Đere (first round)
Marco Cecchinato (second round) Roberto Carballés Baena (second round) Maximilian Marterer (semifinals)
Bjorn Fratangelo (quarterfinals) Stefano Travaglia (quarterfinals)
Taro Daniel (first round)| Semifinals | Final | ||||||||||||
| 1 | Cedrik-Marcel Stebe | 6 | 6 | ||||||||||
| 5 | Maximilian Marterer | 2 | 1 | ||||||||||
| 1 | Cedrik-Marcel Stebe | 6 | 6 | ||||||||||
| Carlos Taberner | 3 | 3 | |||||||||||
| WC |  Adrian Ungur | 3 | 0 | ||||||||||
| Carlos Taberner | 6 | 6 | |||||||||||
| First round | Second round | Quarterfinals | Semifinals | ||||||||||||||||||||||||
| 1 | C-M Stebe | 77 | 77 | ||||||||||||||||||||||||
| WC | Vlad Andrei Dancu | 64 | 64 | 1 | C-M Stebe | 2 | 78 | 6 | |||||||||||||||||||
| Í Cervantes | 77 | 6 | Í Cervantes | 6 | 66 | 2 | |||||||||||||||||||||
| A Arnaboldi | 62 | 1 | 1 | C-M Stebe | 6 | 6 | |||||||||||||||||||||
 J Šátral | 6 | 6 | S Napolitano | 0 | 3 | ||||||||||||||||||||||
| WC |  N Serdarušić | 4 | 2 | J Šátral | 6 | 4 | 3 | ||||||||||||||||||||
| S Napolitano | 6 | 1 | 6 | S Napolitano | 3 | 6 | 6 | ||||||||||||||||||||
| 8 | T Daniel | 2 | 6 | 3 | 1 | C-M Stebe | 6 | 6 | |||||||||||||||||||
| 4 | R Carballés Baena | 6 | 6 | 5 | M Marterer | 2 | 1 | ||||||||||||||||||||
| Q |  A Lazov | 3 | 4 | 4 | R Carballés Baena | 5 | 5 | ||||||||||||||||||||
| V Šafránek | 1 | 0r |  C Ruud | 7 | 7 | ||||||||||||||||||||||
| C Ruud | 6 | 3 | C Ruud | 64 | 3 | ||||||||||||||||||||||
| Q | M Donati | 6 | 6 | 5 | M Marterer | 77 | 6 | ||||||||||||||||||||
| T Robredo | 1 | 4 | Q | M Donati | 4 | 5 | |||||||||||||||||||||
 L Grigelis | 1 | 1 | 5 | M Marterer | 6 | 7 | |||||||||||||||||||||
| 5 | M Marterer | 6 | 6 | ||||||||||||||||||||||||
| First round | Second round | Quarterfinals | Semifinals | ||||||||||||||||||||||||
| 7 | S Travaglia | 6 | 6 | ||||||||||||||||||||||||
| L Giustino | 2 | 0 | 7 | S Travaglia | 6 | 6 | |||||||||||||||||||||
| Q |  A Müller | 1 | 5 | LL | D Kuzmanov | 2 | 0 | ||||||||||||||||||||
| LL | D Kuzmanov | 6 | 7 | 7 | S Travaglia | 3 | 1 | ||||||||||||||||||||
| R Ojeda Lara | 1 | 6 | 2 | WC | A Ungur | 6 | 6 | ||||||||||||||||||||
| WC | A Ungur | 6 | 1 | 6 | WC | A Ungur | 7 | 6 | |||||||||||||||||||
| WC |  Michał Dembek | 1 | 5 | 3 | M Cecchinato | 5 | 3 | ||||||||||||||||||||
| 3 | M Cecchinato | 6 | 7 | WC | A Ungur | 3 | 0 | ||||||||||||||||||||
| 6 | B Fratangelo | 2 | 6 | 79 | C Taberner | 6 | 6 | ||||||||||||||||||||
| Jeremy Jahn | 6 | 3 | 67 | 6 | B Fratangelo | 6 | 6 | ||||||||||||||||||||
| R Bellotti | 6 | 6 | R Bellotti | 4 | 2 | ||||||||||||||||||||||
 M Kližan | 3 | 1 | 6 | B Fratangelo | 3 | 65 | |||||||||||||||||||||
 G Oliveira | 2 | 2 | C Taberner | 6 | 77 | ||||||||||||||||||||||
| C Taberner | 6 | 6 | C Taberner | 6 | 6 | ||||||||||||||||||||||
| Q |  Lenny Hampel | 3 | 6 | 6 | Q | L Hampel | 1 | 2 | |||||||||||||||||||
| 2 | L Đere | 6 | 4 | 1 | |||||||||||||||||||||||
Ričardas Berankis was the defending champion but, no longer competing in junior tennis, did not defend his title.
Grigor Dimitrov was the defending champion, but chose to play in the US Open instead.
Cedrik-Marcel Stebe defeated Amir Weintraub 7–5, 6–1 to win the tournament.
Mikhail Kukushkin was the defending champion but decided not to participate.
Evgeny Donskoy won the title, defeating Marsel İlhan 6–3, 6–4 in the final.
John Isner successfully defended his title by beating Tomáš Berdych 3–6, 6–4, 7–6(11–9) in the final.
Cedrik-Marcel Stebe won the title, beating Yannik Reuter 6–1, 4–6, 6–2
Jamie Murray and John Peers were the defending champions, but Murray chose to participate in the Davis Cup quarterfinals instead. Peers played alongside Henri Kontinen and successfully defended the title, defeating Daniel Nestor and Aisam-ul-Haq Qureshi in the final, 7–5, 6–3.
Roberto Bautista Agut was the defending champion, but lost in the semifinals to David Goffin.
Philipp Kohlschreiber was the defending champion, but lost in the second round to Horacio Zeballos.
Stan Wawrinka was the defending champion and successfully defended his title, defeating Mischa Zverev in the final, 4–6, 6–3, 6–3.
Horacio Zeballos was the defending champion but chose not to defend his title.
Martin Kližan was the defending champion, but withdrew before the tournament began.
Arthur De Greef was the defending champion but chose not to defend his title.
Cedrik-Marcel Stebe was the defending champion but chose not to defend his title.
Cedrik-Marcel Stebe was the defending champion but chose not to defend his title.
Cedrik-Marcel Stebe was the defending champion but chose not to defend his title.
Matteo Berrettini was the defending champion, but withdrew with an ankle injury before the tournament began.
Andrea Collarini was the defending champion but lost in the first round to Marco Cecchinato.
Frances Tiafoe was the defending champion but chose not to defend his title.
Alexander Zverev defeated top seed Stefanos Tsitsipas in the final, 6–4, 7–6(7–3) to win the men's singles tennis title at the 2021 Mexican Open.
Daniel Masur was the defending champion but chose not to defend his title.