The 2020 Hamburg European Open was a men's tennis tournament played on outdoor red clay courts. It was the 114th edition of the German Open Tennis Championships and part of the ATP Tour 500 series of the 2020 ATP Tour (called the Hamburg Open). Originally scheduled for 13 to 19 July 2020, but due to the ongoing COVID-19 pandemic, it was rescheduled from 20 to 27 September 2020 and took place at the Am Rothenbaum in Hamburg, Germany. Fifth-seeded Andrey Rublev won the singles title.

The following players received wildcards into the main draw:

The following player received entry as a special exempt into the main draw:

The following player used a protected ranking into the main draw:

The following players received entry from the qualifying draw:

The following players received entry as a lucky loser:

The following pairs received wildcards into the doubles main draw:

The following pair received entry from the qualifying draw: