The 2018 BMW Open was a men's tennis tournament played on outdoor clay courts. It was the 103rd edition of the event, and part of the ATP World Tour 250 series of the 2018 ATP World Tour. It took place at the MTTC Iphitos complex in Munich, Germany, from 30 April until 6 May 2018.
| Country | Player | Rank1 | Seed | |
|---|---|---|---|---|
| Alexander Zverev | 3 | 1 | ||
 Spain | Roberto Bautista Agut | 15 | 2 | |
 Argentina | Diego Schwartzman | 17 | 3 | |
 Korea, Republic of | Chung Hyeon | 19 | 4 | |
 Italy | Fabio Fognini | 20 | 5 | |
| Philipp Kohlschreiber | 35 | 6 | ||
 France | Gaël Monfils | 41 | 7 | |
 Japan | Yūichi Sugita | 42 | 8 |
The following players received wildcards into the main draw:
The following players received entry as special exempts:
The following players received entry using a protected ranking:
The following players received entry from the qualifying draw:
Andrey Rublev → replaced by 
Mikhail Kukushkin| Country | Player | Country | Player | Rank1 | Seed | |
|---|---|---|---|---|---|---|
 Poland | Łukasz Kubot |  Brazil | Marcelo Melo | 2 | 1 | |
| Ivan Dodig | Rajeev Ram | 37 | 2 | |||
| Nikola Mektić |  Austria | Alexander Peya | 58 | 3 | ||
 Belarus | Max Mirnyi | Austria | Philipp Oswald | 77 | 4 |
The following pairs received wildcards into the doubles main draw:
The following pair received entry as alternates:
See main article: 2018 BMW Open – Singles.
See main article: 2018 BMW Open – Doubles.
Rajeev Ram def. Nikola Mektić / Alexander Peya, 6–3, 7–5
