1 Km.
The Olympiastadion Berlin is located in the district of Charlottenburg-Wilmersdorf and is part of the Olympic grounds, which also include other sports facilities such as the equestrian stadium and the field hockey stadium. The Bundesliga team Hertha BSC uses the Olympiastadion Berlin for its home games in the first Bundesliga, the highest German soccer league. The stadium has a total capacity for about 75,000 people and was extensively renovated in 2004. The stadium is owned by the state of Berlin.
Basically, they have several parking options. You can use one of the free parking lots in the Charlottenburg district, which are located near the Olympic Stadium. However, these are very full on Hertha BSC match days, which is why it can be worth reserving a parking space in one of the parking garages in Charlottenburg.