After completing his secondary education in Mali and university degrees in economics, international development, and social planning in France, he began his professional career as the first Country Director of Terre des Hommes France in Mali in the Timbuktu region, working to improve the health and well-being of the nomadic Tuareg populations.

In Burundi, he contributed to the lifting of the embargo; he negotiated the creation of a humanitarian corridor for the delivery of vaccines and medicines essential to the survival of the population; he launched with President Buyoya the Temporary Schools Program to ensure the education of children displaced by the war.

He organized a reform to transform "UNAIDS into a more focused, effective and efficient joint program capable of delivering results at the country level."

In 2011 in New York, Michel was part of the formulation and launched with Presidents Clinton and Goodluck of the first Global Plan to Eliminate Mother to Child Transmission of HIV.

Sidibé offered his resignation from his post as head of UNAIDS following an expert report[1] on sexual harassment in the agency that criticized his "defective leadership."

[2] In response to heightened scrutiny and reports of his gross mismanagement, however, Sidibé informed the agency's board on 13 December 2018 that he would leave his post in June 2019.

[3] A panel of independent experts released a report on 13 December 2018 saying Sidibé was overseeing a "patriarchal" workplace and promoting a "cult of personality" centered on him as the all-powerful chief.