Petra De Sutter of the Flemish Green party, Groen, was announced as one of the country's Deputy Prime Ministers, according to a statement by the European Greens on Thursday.
De Sutter, who has been a member of the European Parliament since July 2019, was appointed to the post alongside six other politicians, the Reuters news agency reported.
Belgium had not had a full-fledged government since December 2018, when a four-party collation collapsed.
Between the 2019 federal elections and March this year, it was governed by a caretaker administration led by the country's first female Prime Minister, Sophie Wilmes, who is now the country's first female Foreign Minister.
De Sutter is a professor of gynecology, specializing in fertility, at the University of Ghent. She is a vocal advocate for trans rights and reproductive rights, and has spoken openly about her own experiences of being a trans woman.
"I was forty when I decided to fully become the woman that I always were and because of this decision I lost colleagues, people I knew and even friends," she said in an interview published to her website.