In June 2017, Guillaume Gouffier Valente was elected MP for the sixth constituency of Val-de-Marne, comprising the communes of Fontenay-sous-Bois, Saint-Mandé and Vincennes. In 2022, he was re-elected for a second term.

After being a member of the Committee on National Defence and the Armed Forces from 2017 to 2018, he joined the Committee on Constitutional Law, Legislation and the General Administration of the Republic at the National Assembly, where he was appointed whip for the presidential party. He also joined the Delegation for Women's Rights and Equal Opportunities for Men and Women at the National Assembly, where he was elected Vice-Chair in 2022. He is also a member of the Children's Rights Delegation.