| Doubles | |
|---|---|
| 2018 Sparkassen Open | |
| Champions |  Santiago González  Wesley Koolhof |
| Runners-up |  Sriram Balaji Vishnu Vardhan |
| Final score | 6–3, 6–3 |
Julian Knowle and Igor Zelenay were the defending champions but only Zelenay chose to defend his title, partnering Denys Molchanov. Zelenay lost in the quarterfinals to Andre Begemann and Dustin Brown.
Santiago González and Wesley Koolhof won the title after defeating Sriram Balaji and Vishnu Vardhan 6–3, 6–3 in the final.
Santiago González / Wesley Koolhof (champions)
Roman Jebavý / 
Andrés Molteni (quarterfinals)
Denys Molchanov / 
Igor Zelenay (quarterfinals)
Sander Gillé / Joran Vliegen (first round)| First round | Quarterfinals | Semifinals | Final | ||||||||||||||||||||||||
| 1 | S González W Koolhof | 79 | 6 | ||||||||||||||||||||||||
| WC |  Niklas Guttau George von Massow | 67 | 1 | 1 | S González W Koolhof | 77 | 6 | ||||||||||||||||||||
 M Cuevas P Cuevas | 6 | 7 | M Cuevas P Cuevas | 64 | 1 | ||||||||||||||||||||||
| WC | M Möller R Molleker | 4 | 5 | 1 | S González W Koolhof | 6 | 6 | ||||||||||||||||||||
| 3 | D Molchanov I Zelenay | 6 | 61 | [10] | A Begemann D Brown | 0 | 3 | ||||||||||||||||||||
 S Ofner  S Travaglia | 2 | 77 | [3] | 3 | D Molchanov I Zelenay | 3 | 4 | ||||||||||||||||||||
| A Begemann D Brown | 77 | 6 | A Begemann D Brown | 6 | 6 | ||||||||||||||||||||||
 T Bednarek  R Junaid | 62 | 2 | 1 | S González W Koolhof | 6 | 6 | |||||||||||||||||||||
 H-y Peng T-S Weissborn | 7 | 6 | S Balaji V Vardhan | 3 | 3 | ||||||||||||||||||||||
F Agamenone  H Dellien | 5 | 2 | H-y Peng T-S Weissborn | 6 | 4 | [8] | |||||||||||||||||||||
| WC |  N Kuhn  C Ruud | 6 | 64 | [10] | WC | N Kuhn C Ruud | 2 | 6 | [10] | ||||||||||||||||||
| 4 | S Gillé J Vliegen | 4 | 77 | [6] | WC | N Kuhn C Ruud | 6 | 65 | [10] | ||||||||||||||||||
| S Balaji V Vardhan | 6 | 6 | S Balaji V Vardhan | 4 | 77 | [12] | |||||||||||||||||||||
 F Neis  R Roelofse | 4 | 3 | S Balaji V Vardhan | 67 | 6 | [10] | |||||||||||||||||||||
 R Arneodo A Vavassori | 3 | 3 | 2 | R Jebavý A Molteni | 79 | 4 | [8] | ||||||||||||||||||||
| 2 | R Jebavý A Molteni | 6 | 6 | ||||||||||||||||||||||||
Harri Heliövaara and Denys Molchanov were the defending champions but Heliövaara decided not to participate.
Molchanov played alongside Uladzimir Ignatik.
Andre Begemann and Martin Emmrich won the title by defeating Rameez Junaid and Frank Moser 6–7(2–7), 7–6(7–2), [10–8] in the final.
Andre Begemann and Tim Pütz were the defending champion, but Begemann decided not to compete this year. Pütz played alongside Dominik Meffert and reached the final.
Nicolás Almagro and Carlos Berlocq were the defending champions, but Almagro chose not to participate this year and Berlocq chose to compete in Umag instead.
Wesley Koolhof and Matwé Middelkoop were the defending champions but chose not to defend their title.
Ilija Bozoljac and Igor Zelenay were the defending champions but only Zelenay chose to defend his title, partnering Denys Molchanov. Zelenay lost in the quarterfinals to Ken and Neal Skupski.
Jonathan Eysseric and André Ghem were the defending champions but chose not to defend their title.
Sanchai and Sonchat Ratiwatana were the defending champions but chose not to defend their title.
Marco Cecchinato and Matteo Donati were the defending champions but only Donati chose to defend his title, partnering Simone Bolelli. Donati lost in the first round to Nikola Milojević and Mohamed Safwat.
Pierre-Hugues Herbert and Adil Shamasdin were the defending champions but only Shamasdin chose to defend his title, partnering Sander Arends. Shamasdin lost in the quarterfinals to Dennis Novak and Tristan-Samuel Weissborn.
Julian Knowle and Igor Zelenay were the defending champions but only Zelenay chose to defend his title, partnering Denys Molchanov. Zelenay lost in the semifinals to Ariel Behar and Máximo González.
Guillermo Durán and Andrés Molteni were the defending champions but chose not to defend their title.
Oliver Marach and Philipp Oswald were the defending champions, but they chose to compete alongside different partners in Hamburg instead.
Wesley Koolhof and Artem Sitak were the defending champions but chose not to defend their title.
Jonathan Erlich and Divij Sharan were the defending champions but chose not to defend their title.
Julian Ocleppo and Andrea Vavassori were the defending champions but lost in the first round to Jonathan Eysseric and Andrei Vasilevski.
Dominic Inglot and Franko Škugor were the defending champions, but Škugor chose to compete in Barcelona instead. Inglot played alongside Rohan Bopanna, but lost in the quarterfinals to Andre Begemann and Ernests Gulbis.
Rameez Junaid and David Pel were the defending champions but only Junaid chose to defend his title, partnering Jozef Kovalík. Junaid lost in the quarterfinals to Andre Begemann and Fabrice Martin.
Marcelo Demoliner and Santiago González were the defending champions, but chose not to participate together. Demoliner played alongside Divij Sharan, but lost in the quarterfinals to Denys Molchanov and Igor Zelenay. González teamed up with Aisam-ul-Haq Qureshi, but lost in the first round to Ivan Dodig and Filip Polášek.
Denys Molchanov and Igor Zelenay were the defending champions but chose to defend their title with different partners. Molchanov partnered Hans Podlipnik Castillo but lost in the quarterfinals to Jebavý and Zelenay. Zelenay partnered Roman Jebavý but lost in the final to Frederik Nielsen and Tim Pütz.
Kevin Krawietz and Andreas Mies were the defending champions and successfully defended their title, defeating Mate Pavić and Bruno Soares in the final, 6–3, 7–5.