The energy supplier plans to build a 35MW onshore wind farm in Hessen, near Frankfurt.
The project is expected to become operational by the end of 2023 – once built, it is predicted to generate almost 100,000MWh, enough to power nearly 40,000 homes a year.
Octopus aims to operate 1.2GW of wind and solar farms across the country by 2030.
Andrew Mack, Chief Executive Officer of Octopus Energy Germany, said: “We’ve been blown away by the response to Octopus in the German retail energy market.
“This first onshore wind deal is a really significant milestone and it’s just the beginning, bringing green generation even closer to the consumer.”