The Norwegian capital is vying for the title, which can be won by any European town with more than 100,000 inhabitants, against Essen (Germany), Ljubljana (Slovenia), Nijmegen (The Netherlands), and Umeå (Sweden).
“There is great diversity in this shortlist, with cities large and small competing to win the title of European Green Capital 2016," said EU Environment Commissioner Janez Potočnik in a press release. "It's encouraging to see the quality of these applications, which all feature local authorities partnering with citizens to improve the urban environment and encourage sustainable development.”
Oslo has previously lagged behind its Scandinavian rivals, with Stockholm winning the Green Capital title in 2010, and Copenhagen in 2014.
The city was a finalist in the competition for the Green Capital 2010 and 2011.
Teams from the shortlisted cities will appear before a jury in Copenhagen on 23 June, when they will argue their city's claim the title, with the award announced the following day at an official ceremony.