Journalist, diplomat, and politician. In 1985–1989, he took part in the democratic opposition as an activist in the School Clubs for Social Resistance (Szkolne Koła Oporu Społecznego) and Independent Students Association (Niezależne Zrzeszenie Studentów). He also worked as an editor in the underground press, later writing the book Podziemie w Cegielskim (Underground at the Cegielski Plant).

In 1994, he graduated from Adam Mickiewicz University in Poznań with a master’s degree in history.

In 1990, Bosacki started working at Gazeta Wyborcza daily, first as an editorial assistant for the Poznań local edition, and later as a politics editor and head of the world news section.

In 2007–2010, he served as Gazeta Wyborcza’s Washington correspondent.

In 2010, he became spokesperson for the Ministry of Foreign Affairs, and in September 2013, was appointed Poland’s ambassador to Canada.

Bosacki has worked with many foreign media outlets and think tanks, including the German Marshall Fund and the Center for European Policy Analysis in Washington.

In 2019, he was elected from Poznań to the Polish Senate, where served as head of the Civic Coalition party club.

Since 2023, he has served as a Civic Coalition deputy in the Sejm of the 10th term.

Secretary of State Marcin Bosacki oversees the Department for Strategic Communications and Countering Foreign Disinformation and cooperates with Undersecretary of State Robert Kupiecki in matters regarding countering disinformation as hybrid threats. He is responsible for social dialogue and the citizen dimension of foreign policy, information and educational activities concerning European integration as well as the EU enlargement and neighbourhood policy. Moreover, he coordinates the promotion of Poland and Poland’s economy abroad, supervising the Department of Promotion and Cultural Diplomacy, and accepts the adoption of new priorities for provincial foreign cooperation and the undertaking of provincial foreign initiatives.