Teams made up of athletes representing different National Olympic Committees (NOCs), called mixed-NOCs teams, participated in the 2018 Summer Youth Olympics. These teams participated in either events composed entirely of mixed-NOCs teams, or in events which saw the participation of mixed-NOCs teams and non-mixed-NOCs teams. When a mixed-NOCs team won a medal, the Olympic flag was raised rather than a national flag; if a mixed-NOCs team won gold, the Olympic anthem would be played instead of national anthems. A total of 18 events with Mixed NOCs were held.

Tonya Paulsson is a Swedish artistic gymnast. She is the 2019 and 2020 Swedish National Champion and she represented Sweden at the 2018 Youth Olympics where she was part of the Mixed NOC team who won bronze in the mixed multi-discipline team competition.