| Date: | July 23–29 |
| Edition: | 112th |
| Surface: | Clay / Outdoor |
| Category: | ATP World Tour 500 |
| Location: | Hamburg, Germany |
| Venue: | Am Rothenbaum |
| Champs: |  Nikoloz Basilashvili |
| Champd: | Julio Peralta /  Horacio Zeballos |
| Main Name: | German Open Tennis Championships |
| After Name: | Hamburg European Open |
The 2018 German Open (also known as the 2018 German Tennis Championships) was a men's tennis tournament played on outdoor red clay courts. It was the 112th edition of the German Open Tennis Championships and part of the ATP World Tour 500 series of the 2018 ATP World Tour. It took place at the Am Rothenbaum in Hamburg, Germany, from July 23 through 29, 2018.
| Event | W | F | SF | QF | Round of 16 | Round of 32 | width=85 | Q | width=85 | Q2 | width=85 | Q1 |
| Singles[1] | 500 | 300 | 180 | 90 | 45 | 0 | 20 | 10 | 0 | |||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubles | 0 | 45 | 25 | 0 |
| width=130 bgcolor=dfe2e9 | Event | width=80 bgcolor=lime | W | width=85 bgcolor=thistle | F | width=85 bgcolor=ffff00 | SF | width=85 bgcolor=ffebcd | QF | width=85 bgcolor=afeeee | Round of 16 | width=85 bgcolor=afeeee | Round of 32 | width=85 | Q2 | width=85 | Q1 |
| style=background:#ededed | Singles | €349,200 | €171,195 | €86,145 | €43,810 | €22,750 | €12,000 | €2,655 | €1,355 | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| style=background:#ededed | Doubles | €105,140 | €51,470 | €25,820 | €13,250 | €6,850 |
| Country | Player | Rank1 | Seed | |
|---|---|---|---|---|
 Austria | Dominic Thiem[2] | 4 | 1 | |
| Argentina | Diego Schwartzman | 12 | 2 | |
 Spain | Pablo Carreño Busta | 13 | 3 | |
 Bosnia and Herzegovina | Damir Džumhur | 23 | 4 | |
| Philipp Kohlschreiber | 24 | 5 | ||
 Italy | Marco Cecchinato | 27 | 6 | |
 France | Richard Gasquet | 29 | 7 | |
| Spain | Fernando Verdasco | 33 | 8 |
The following players received wildcards into the main draw:
The following player received entry as a special exempt:
The following players received entry from the qualifying draw:
The following player received entry as a lucky loser:
Filip Krajinović → replaced by Aljaž Bedene Lucas Pouille → replaced by Nicolás Jarry Andreas Seppi → replaced by 
Thiago Monteiro| Country | Player | Country | Player | Rank1 | Seed | |
|---|---|---|---|---|---|---|
| Austria | Oliver Marach | Mate Pavić | 5 | 1 | ||
| Ivan Dodig | Jean-Julien Rojer | 29 | 2 | |||
| Nikola Mektić | Austria | Alexander Peya | 42 | 3 | ||
| Pablo Cuevas | Spain | Marc López | 50 | 4 |
The following pairs received wildcards into the doubles main draw:
The following pair received entry from the qualifying draw:
See main article: 2018 German Open – Singles.
Nikoloz Basilashvili def. Leonardo Mayer, 6–4, 0–6, 7–5See main article: 2018 German Open – Doubles.
Horacio Zeballos def. Oliver Marach / Mate Pavić, 6–1, 4–6, [10–6]