| Singles | |
|---|---|
| 2015 Tilia Slovenia Open | |
| Champion |  Luca Vanni |
| Runner-up |  Grega Žemlja |
| Score | 6–3, 7–6(8–6) |
Blaž Kavčič was the defending champion, but chose not to compete.
Luca Vanni won the tournament, defeating Grega Žemlja in the final, 6–3, 7–6(8–6).
Marcel Granollers (first round) Paolo Lorenzi (quarterfinals)
Kimmer Coppejans (first round)
Lukáš Lacko (second round) Norbert Gombos (semifinals) Luca Vanni (champion)
Thiemo de Bakker (second round)
Mirza Bašić (quarterfinals)| Semifinals | Final | ||||||||||||
| 5 | Norbert Gombos | 7 | 4 | 3 | |||||||||
| 6 | Luca Vanni | 5 | 6 | 6 | |||||||||
| 6 | Luca Vanni | 6 | 78 | ||||||||||
| WC | Grega Žemlja | 3 | 66 | ||||||||||
| WC | Grega Žemlja | 6 | 6 | ||||||||||
 Alexander Kudryavtsev | 4 | 2 | |||||||||||
| First round | Second round | Quarterfinals | Semifinals | ||||||||||||||||||||||||
| 1 | M Granollers | 64 | 2 | ||||||||||||||||||||||||
| E Donskoy | 77 | 6 | E Donskoy | 6 | 3 | 6 | |||||||||||||||||||||
 C Hemery | 6 | 5 | 6 | C Hemery | 4 | 6 | 3 | ||||||||||||||||||||
| Q | Edoardo Eremin | 3 | 7 | 3 | E Donskoy | 6 | 2 | 3 | |||||||||||||||||||
 P Gojowczyk | 3 | 6 | 6 | 5 | N Gombos | 2 | 6 | 6 | |||||||||||||||||||
 L Djere | 6 | 3 | 2 | P Gojowczyk | 4 | 3 | |||||||||||||||||||||
| K Kravchuk | 1 | 6 | 64 | 5 | N Gombos | 6 | 6 | ||||||||||||||||||||
| 5 | N Gombos | 6 | 4 | 77 | 5 | N Gombos | 7 | 4 | 3 | ||||||||||||||||||
| 3 | K Coppejans | 1 | 2 | 6 | L Vanni | 5 | 6 | 6 | |||||||||||||||||||
| LL | J Eysseric | 6 | 6 | LL | J Eysseric | 62 | 3 | ||||||||||||||||||||
 H Moriya | 1 | 1 | WC | A Radinski | 77 | 6 | |||||||||||||||||||||
| WC | A Radinski | 6 | 6 | WC | A Radinski | 2 | 0 | ||||||||||||||||||||
| N Desein | 1 | 0r | 6 | L Vanni | 6 | 6 | |||||||||||||||||||||
| G Gigounon | 6 | 1 | G Gigounon | 1 | 3 | ||||||||||||||||||||||
| A Karatsev | 3 | 2 | 6 | L Vanni | 6 | 6 | |||||||||||||||||||||
| 6 | L Vanni | 6 | 6 | ||||||||||||||||||||||||
| First round | Second round | Quarterfinals | Semifinals | ||||||||||||||||||||||||
| 8 | M Bašić | 6 | 2 | 6 | |||||||||||||||||||||||
| M Viola | 2 | 6 | 4 | 8 | M Bašić | 6 | 6 | ||||||||||||||||||||
| J Kovalík | 3 | 2 | WC |  C İlkel | 2 | 2 | |||||||||||||||||||||
| WC | C İlkel | 6 | 6 | 8 | M Bašić | 77 | 5 | 3 | |||||||||||||||||||
| WC | G Žemlja | 6 | 5 | 6 | WC | G Žemlja | 65 | 7 | 6 | ||||||||||||||||||
| A Arnaboldi | 4 | 7 | 1 | WC | G Žemlja | 6 | 6 | ||||||||||||||||||||
| WC | Aljaž Jakob Kaplja | 2 | 1 | 4 | L Lacko | 0 | 2 | ||||||||||||||||||||
| 4 | L Lacko | 6 | 6 | WC | G Žemlja | 6 | 6 | ||||||||||||||||||||
| 7 | T de Bakker | 7 | 6 | A Kudryavtsev | 4 | 2 | |||||||||||||||||||||
| Q |  J Milton | 5 | 3 | 7 | T de Bakker | 77 | 2 | 2 | |||||||||||||||||||
| A Kudryavtsev | 78 | 6 | A Kudryavtsev | 63 | 6 | 6 | |||||||||||||||||||||
| Q | R Ghedin | 66 | 3 | A Kudryavtsev | 6 | 1 | 6 | ||||||||||||||||||||
| Q |  C Garin | 5 | 6 | 5 | 2 | P Lorenzi | 4 | 6 | 1 | ||||||||||||||||||
| Alt | D Guez | 7 | 2 | 7 | Alt | D Guez | 3 | 4 | |||||||||||||||||||
| A Šetkić | 79 | 1 | 3 | 2 | P Lorenzi | 6 | 6 | ||||||||||||||||||||
| 2 | P Lorenzi | 67 | 6 | 6 | |||||||||||||||||||||||
Benjamin Becker was the defending champion, but he did not compete that year.
Federico Delbonis was the defending champion, but lost to Facundo Bagnis in the first round.
Pablo Cuevas won the title, defeating Luca Vanni in the final, 6–4, 3–6, 7–6(7–4).
Andy Murray defeated the two-time defending champion Rafael Nadal in the final, 6–3, 6–2 to win the men's singles tennis title at the 2015 Madrid Open. It was his second title in as many weeks.
Kei Nishikori was the defending champion but chose not to participate this year. Three-time losing finalist Julien Benneteau did not participate either.
Ivan Dodig won the title, defeating Michael Berrer in the final 6–2, 6–1.
Ivo Karlović was the defending champion, but lost to John-Patrick Smith in the first round.
Aljaž Bedene was the defending champion but chose not to participate.
Richard Gasquet was the defending champion, but chose not to participate this year.
Mirza Bašić was the defending champion but chose not to participate.
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.
Ivan Dodig was the defending champion but chose not to defend his title.
Marius Copil was the defending champion but lost in the quarterfinals to Jürgen Melzer.
Jordan Thompson was the defending champion but chose not to defend his title.
Thomas Fabbiano was the defending champion but lost to Evgeny Donskoy 6–3, 6–4 in the final.
Federico Delbonis was the defending champion but retired in the first round against Reda El Amrani.
Jordan Thompson was the defending champion but lost in the quarterfinals to Quentin Halys.
Luca Vanni was the defending champion but chose not to defend his title.
Sergiy Stakhovsky was the defending champion but lost in the quarterfinals to Constant Lestienne.
Damir Džumhur was the defending champion, but lost in the quarterfinals to Stan Wawrinka.
Mirza Bašić was the defending champion but lost in the first round to Martin Kližan.