| Singles | |
|---|---|
| 2018 Poprad-Tatry ATP Challenger Tour | |
| Champion |  Jozef Kovalík |
| Runner-up |  Arthur De Greef |
| Score | 6–4, 6–0 |
Cedrik-Marcel Stebe was the defending champion but chose not to defend his title.
Jozef Kovalík won the title after defeating Arthur De Greef 6–4, 6–0 in the final.
Gerald Melzer (second round, retired)
Casper Ruud (second round)
Adam Pavlásek (quarterfinals) Jozef Kovalík (champion)
Mohamed Safwat (quarterfinals)
Attila Balázs (semifinals) Dennis Novak (quarterfinals)
Uladzimir Ignatik (first round)| Semifinals | Final | ||||||||||||
| Zdeněk Kolář | 1 | 2 | |||||||||||
| 4 | Jozef Kovalík | 6 | 6 | ||||||||||
| 4 | Jozef Kovalík | 6 | 6 | ||||||||||
| Arthur De Greef | 4 | 0 | |||||||||||
| 6 | Attila Balázs | 1 | 3 | ||||||||||
| Arthur De Greef | 6 | 6 | |||||||||||
| First round | Second round | Quarterfinals | Semifinals | ||||||||||||||||||||||||
| 1 | G Melzer | 6 | 6 | ||||||||||||||||||||||||
| Q | Pavel Nejedlý | 2 | 2 | 1 | G Melzer | 4 | 0r | ||||||||||||||||||||
 B Rola | 4 | 3 | Z Kolář | 6 | 0 | ||||||||||||||||||||||
| Z Kolář | 6 | 6 | Z Kolář | 6 | 6 | ||||||||||||||||||||||
 A Pavić | 4 | 2 | 7 | D Novak | 2 | 2 | |||||||||||||||||||||
| M Neuchrist | 6 | 6 | M Neuchrist | 2 | 4 | ||||||||||||||||||||||
| L Rosol | 1 | 5 | 7 | D Novak | 6 | 6 | |||||||||||||||||||||
| 7 | D Novak | 6 | 7 | Z Kolář | 1 | 2 | |||||||||||||||||||||
| 4 | J Kovalík | 6 | 7 | 4 | J Kovalík | 6 | 6 | ||||||||||||||||||||
 T Brkić | 4 | 5 | 4 | J Kovalík | 6 | 7 | |||||||||||||||||||||
 T-h Yang | 6 | 6 | T-h Yang | 2 | 5 | ||||||||||||||||||||||
| Q | J Šátral | 4 | 2 | 4 | J Kovalík | 67 | 77 | 6 | |||||||||||||||||||
| Q | A Haider-Maurer | 6 | 6 | 5 | M Safwat | 79 | 65 | 4 | |||||||||||||||||||
| Marek Jaloviec | 3 | 4 | Q | A Haider-Maurer | 5 | 6 | 4 | ||||||||||||||||||||
| WC | Peter Vajda | 1 | 1 | 5 | M Safwat | 7 | 1 | 6 | |||||||||||||||||||
| 5 | M Safwat | 6 | 6 | ||||||||||||||||||||||||
| First round | Second round | Quarterfinals | Semifinals | ||||||||||||||||||||||||
| 6 | A Balázs | 6 | 6 | ||||||||||||||||||||||||
 M Viola | 3 | 3 | 6 | A Balázs | 6 | 6 | |||||||||||||||||||||
 P Krstin | 5 | 6 | 62 | V Šafránek | 1 | 0 | |||||||||||||||||||||
| V Šafránek | 7 | 4 | 77 | 6 | A Balázs | 6 | 6 | ||||||||||||||||||||
| WC | Andrej Glváč | 4 | 6 | 6 | 3 | A Pavlásek | 2 | 4 | |||||||||||||||||||
| WC | Dominik Šproch | 6 | 0 | 2 | WC | A Glváč | 2 | 0 | |||||||||||||||||||
| Q |  F Dancevic | 5 | 0r | 3 | A Pavlásek | 6 | 6 | ||||||||||||||||||||
| 3 | A Pavlásek | 7 | 0 | 6 | A Balázs | 1 | 3 | ||||||||||||||||||||
| 8 | U Ignatik | 2 | 6 | 3 | A De Greef | 6 | 6 | ||||||||||||||||||||
| A De Greef | 6 | 3 | 6 | A De Greef | 77 | 6 | |||||||||||||||||||||
 D Muñoz de la Nava | 2 | 4 | F Horanský | 62 | 3 | ||||||||||||||||||||||
| F Horanský | 6 | 6 | A De Greef | 6 | 7 | ||||||||||||||||||||||
| S Gutiérrez Ferrol | 6 | 3 | S Gutiérrez Ferrol | 2 | 5 | ||||||||||||||||||||||
| M Zekić | 2 | 0r | S Gutiérrez Ferrol | 6 | 6 | ||||||||||||||||||||||
| WC | L Klein | 4 | 1r | 2 | C Ruud | 4 | 1 | ||||||||||||||||||||
| 2 | C Ruud | 6 | 1 | ||||||||||||||||||||||||
Víctor Estrella Burgos was the defending champion and successfully defended his title, defeating Thomaz Bellucci in the final, 4–6, 7–6(7–5), 6–2.
Andy Murray was the defending champion, but chose not to participate this year.
Luca Vanni was the defending champion but chose not to defend his title.
Tomáš Berdych was the defending champion and successfully defended his title, defeating Richard Gasquet in the final, 7−6(7−5), 6−7(2−7), 6−3.
Dominic Thiem was the defending champion, but chose to compete in Rotterdam instead.
Pablo Cuevas was the two-time defending champion and successfully defended his title, defeating Albert Ramos Viñolas in the final, 6–7(3–7), 6–4, 6–4.
Philipp Kohlschreiber was the defending champion, but lost in the second round to Horacio Zeballos.
Grigor Dimitrov was the defending champion, but withdrew before the tournament because of a shoulder injury.
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. With the win, Nadal retained the ATP no. 1 singles ranking. It was Nadal's record-extending eleventh Barcelona Open title and his 20th ATP 500 title overall, equaling Roger Federer's record. It was Tsitsipas' maiden ATP Tour final.
Nicola Kuhn was the defending champion but lost in the first round to Yannick Hanfmann.
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.
Roberto Carballés Baena was the defending champion but retired in the third round against Jozef Kovalík.
Marco Cecchinato was the defending champion, but lost in the first round to Roberto Carballés Baena.
Jozef Kovalík was the defending champion but lost in the quarterfinals to Carlos Taberner.
Lorenzo Sonego defeated defending champion Laslo Đere in the final, 2–6, 7–6(7–5), 6–4 to win the men's singles title at the 2021 Sardegna Open. With the victory, Sonego became the first Italian in 15 years to capture an ATP Tour title on home soil.
Miomir Kecmanović was the defending champion, but chose to compete at the Summer Olympics instead.
Jozef Kovalík was the defending champion but chose not to defend his title.
Tommy Paul defeated the defending champion, Denis Shapovalov, in the final, 6–4, 2–6, 6–4, to win the singles title at the 2021 Stockholm Open. This was Paul's first ATP Tour title.
Roberto Bautista Agut defeated the defending champion Nikoloz Basilashvili in a rematch of the previous year's final, 6–3, 6–4 to win the singles title at the 2022 Qatar Open.
Tallon Griekspoor was the defending champion but chose not to defend his title.