Marie-Colline Leroy was born in Vaudignies, small village between Ath and Mons, in 1984. She graduated from Université Libre de Bruxelles (ULB) to become a French teacher. For a long time, she has been training, preparing and educating future teachers notably on the questions of gender stereotypes.

It was not until 2009 that she started her political career among the political party - Ecolo. She became the co-president of Ecolo-Picardie from 2015 to 2017 and, from 2018, she came to be head of the list for the local elections in Frasnes-les-Anvaing, among the communal council. Then, she became a federal member of the parliament in 2019. In the Chamber of Representatives, she ensured the presidency of the Social Affairs Commission, during which she devoted herself to equal and fair social security. She was, among other things, very invested in the reform of the status of workers from the artistic and cultural fields. She is also involved in favor of a parental leave, along with the files on pensions. In 2023, she has been selected to take on the role of State Secretary for Gender Equality, Gender Opportunities and Diversity.

Very committed to the questions of education, gender and equality, her political motto is : "Fight against poverty and leave no one behind".