| Singles | |
|---|---|
| 2024 HPP Open | |
| Champion |  Kei Nishikori |
| Runner-up |  Luca Nardi |
| Score | 3–6, 6–4, 6–1 |
Corentin Moutet was the defending champion [1] but chose not to defend his title.
Kei Nishikori won the title after defeating Luca Nardi 3–6, 6–4, 6–1 in the final. [2]
Gabriel Diallo (withdrew)
Borna Ćorić (withdrew)
Otto Virtanen (quarterfinals)
Jacob Fearnley (quarterfinals) Luca Nardi (final)
Mikhail Kukushkin (first round)
Jérôme Kym (second round)
Maximilian Marterer (second round)| Semifinals | Final | ||||||||||||
| Q | Max Hans Rehberg | 4 | 78 | 2 | |||||||||
| Kei Nishikori | 6 | 66 | 6 | ||||||||||
| Kei Nishikori | 3 | 6 | 6 | ||||||||||
| 5 | Luca Nardi | 6 | 4 | 1 | |||||||||
| Denis Yevseyev | 6 | 3 | 64 | ||||||||||
| 5 | Luca Nardi | 2 | 6 | 77 | |||||||||
| First round | Second round | Quarterfinals | Semifinals | ||||||||||||||||||||||||
| LL |  R Berankis | 3 | 4 | ||||||||||||||||||||||||
| H Squire | 6 | 6 | H Squire | 7 | 6 | ||||||||||||||||||||||
| A Pellegrino | 6 | 6 | A Pellegrino | 5 | 4 | ||||||||||||||||||||||
| Q |  Alexis Gautier | 3 | 1 | H Squire | 65 | 65 | |||||||||||||||||||||
| Q | MH Rehberg | 6 | 1 | 6 | Q | MH Rehberg | 77 | 77 | |||||||||||||||||||
| Q | G Blancaneaux | 4 | 6 | 3 | Q | MH Rehberg | 77 | 6 | |||||||||||||||||||
 S Rodríguez Taverna | 3 | 3 | 8 | M Marterer | 65 | 4 | |||||||||||||||||||||
| 8 | M Marterer | 6 | 6 | Q | MH Rehberg | 4 | 78 | 2 | |||||||||||||||||||
| 4 | J Fearnley | 6 | 6 | K Nishikori | 6 | 66 | 6 | ||||||||||||||||||||
| V Royer | 2 | 3 | 4 | J Fearnley | 6 | 6 | |||||||||||||||||||||
 A Kachmazov | 1 | 2 |  Em Nava | 4 | 3 | ||||||||||||||||||||||
| Em Nava | 6 | 6 | 4 | J Fearnley | 4 | 3 | |||||||||||||||||||||
| K Nishikori | 6 | 6 | K Nishikori | 6 | 6 | ||||||||||||||||||||||
| Q |  N Álvarez Varona | 4 | 2 | K Nishikori | 6 | 1 | 6 | ||||||||||||||||||||
| Q |  A Shelbayh | 2 | 1 | 7 | J Kym | 3 | 6 | 2 | |||||||||||||||||||
| 7 | J Kym | 6 | 6 | ||||||||||||||||||||||||
| First round | Second round | Quarterfinals | Semifinals | ||||||||||||||||||||||||
| 6 | M Kukushkin | 4 | 5 | ||||||||||||||||||||||||
| Alt | F Arnaboldi | 6 | 7 | Alt | F Arnaboldi | 2 | 4 | ||||||||||||||||||||
| D Yevseyev | 6 | 6 | D Yevseyev | 6 | 6 | ||||||||||||||||||||||
| WC |  O Ojakäär | 2 | 4 | D Yevseyev | 6 | 7 | |||||||||||||||||||||
| WC | Patrick Kaukovalta | 6 | 4 | 78 | 3 | O Virtanen | 4 | 5 | |||||||||||||||||||
| WC | Oskari Paldanius | 3 | 6 | 66 | WC | P Kaukovalta | 3 | 2 | |||||||||||||||||||
| Alt | R Molleker | 4 | 3 | 3 | O Virtanen | 6 | 6 | ||||||||||||||||||||
| 3 | O Virtanen | 6 | 6 | D Yevseyev | 6 | 3 | 64 | ||||||||||||||||||||
| 5 | L Nardi | 6 | 0 | 5 | L Nardi | 2 | 6 | 77 | |||||||||||||||||||
| SE |  G Oliveira | 3 | 0r | 5 | L Nardi | 78 | 77 | ||||||||||||||||||||
 A Holmgren | 6 | 6 | A Holmgren | 66 | 62 | ||||||||||||||||||||||
| E Butvilas | 4 | 1 | 5 | L Nardi | 6 | 6 | |||||||||||||||||||||
| Q |  Sandro Kopp | 2 | 1 | J Choinski | 4 | 3 | |||||||||||||||||||||
| J Choinski | 6 | 6 | J Choinski | 0 | 6 | 6 | |||||||||||||||||||||
 J Fonseca | 6 | 6 | J Fonseca | 6 | 1 | 2 | |||||||||||||||||||||
| LL |  J Sels | 2 | 3 | ||||||||||||||||||||||||
Juan Ignacio Chela was the defending champion, but could not defend his title since he withdrew from the tournament for personal reasons.
In the final match, Ryan Sweeting claimed the title, defeating Kei Nishikori 6–4, 7–6(7–3).
Novak Djokovic defeated the defending champion Andy Murray in the final, 6–2, 3–6, 6–3, to win the men's singles tennis title at the 2016 Madrid Open. It was Djokovic's second title in Madrid and his record 29th ATP Masters 1000 title.
Andy Murray defeated the two-time defending champion Novak Djokovic in the final, 6–3, 6–3 to win the men's singles tennis title at the 2016 Italian Open.
Andy Murray defeated John Isner in the final, 6–3, 6–7(4–7), 6–4 to win the singles tennis title at the 2016 Paris Masters. By reaching the final, Murray secured the world No. 1 ranking for the first time in his career.
Dominic Thiem was the defending champion, but lost in the quarterfinals to Fernando Verdasco.
Two-time defending champion Rafael Nadal defeated Stefanos Tsitsipas in the final, 6–2, 6–1 to win the singles tennis title at the 2018 Barcelona Open. Nadal did not drop a set en route to his record-extending eleventh Barcelona Open title and his 20th ATP 500 title overall, equaling Roger Federer's record. He retained the world No. 1 singles ranking with the win. It was Tsitsipas' first ATP Tour final.
Leonardo Mayer was the defending champion, but lost in the final to Nikoloz Basilashvili, 4–6, 6–0, 5–7. This was Basilashvili's first ATP World Tour title, as well as the first ATP title won by a Georgian player since Alexander Metreveli.
Peter Gojowczyk was the defending champion, but lost to Kei Nishikori in the second round.
Roger Federer was the defending champion, but chose not to participate this year.
Félix Auger-Aliassime was the defending champion but chose not to defend his title.
Corentin Moutet was the defending champion but chose not to defend his title.
In the 2021 French Open – Boys' doubles, Flavio Cobolli and Dominic Stricker were the defending champions, but both players were no longer eligible to participate in junior events.
Pavel Kotov was the defending champion but chose not to participate.
Pablo Cuevas was the defending champion but chose not to defend his title.
Oscar Otte was the defending champion but chose not to defend his title.
Corentin Moutet was the defending champion but chose not to defend his title.
James Duckworth was the defending champion but lost in the second round to Miljan Zekić.
Hong Seong-chan was the defending champion but lost in the first round to Luca Nardi.
Yosuke Watanuki was the defending champion but chose not to defend his title.
Lorenzo Musetti was the defending champion but chose not to defend his title.