Östlund was born Claes Olle Ruben Östlund in Styrsö, Gothenburg Municipality, Sweden. After high school, he started working in various ski resorts in the Alps during the winter seasons. While in the Alps, he began making skiing videos for his friends, which helped him obtain a job at a local production company.
He went on to study at the Gothenburg film school, graduating in 2001. He was accepted to the school based on his skiing films. Together with film producer Erik Hemmendorff, he is the co-founder of the production company Plattform Produktion, which produces his films.
