Although Lindelöf was not named in the final squad for the UEFA European Under-21 Championship, on 15 June 2015 he replaced defender Emil Krafth who was ruled out of the tournament after a back injury. He made his debut in the tournament in the first game against Italy. On 30 June 2015 he successfully converted Sweden's fifth and last penalty against Portugal in a 4–3 penalty shoot-out victory in the final to become European under-21 champion. He was named in the Team of the Tournament.