On 24 March 2016, Semedo marked his debut for the Portugal under-21 team with a goal, scoring the opener in a 4–0 home defeat of Liechtenstein in the 2017 UEFA European Under-21 Championship qualifiers played in Ponta Delgada. In October 2019, while still awaiting trial for alleged crimes in Spain, he received his first call-up for the senior team ahead of UEFA Euro 2020 qualification matches against Luxembourg and Ukraine.