Marcondes made 43 appearances and scored 10 goals for Denmark between U17 and U21 level. He was a part of the U21 squad which exited in the group stage at the 2017 UEFA European U21 Championship. Marcondes was called into the Denmark U21 squad for the Suwon Invitational Tournament, into which the team was entered in preparation for the 2016 Summer Olympics. Despite appearing in each match and scoring one goal, he was not named in the Olympic squad.