Sinkevičius, a long-serving municipal politician from the central Lithuanian town of Jonava, is the third Social Democrat to serve as prime minister since the party won the 2024 parliamentary election. He replaces Inga Ruginienė, who resigned last week after the ruling coalition was reshuffled.
"I will strive to be a Prime Minister who unites rather than divides, who listens and is not afraid to make decisions," Sinkevičius told parliamentarians.
The 42-year-old politician now has 15 days to form a cabinet and prepare the government's programme, both of which must be coordinated with President Gitanas Nausėda and approved by the Seimas.
Sinkevičius' political career has been closely tied to Jonava, which he has led as mayor, with interruptions, since 2011.
In 2016, he briefly served as economy minister, leaving office less than a year later after the Social Democrats withdrew from the coalition with the Lithuanian Farmers and Greens Union.
His political career was temporarily derailed after Lithuania's Laisvės TV reported that he had used municipal funds to purchase two televisions and other communications services.
The allegations led to criminal proceedings, but the Supreme Court of Lithuania ultimately dismissed the case, paving the way for Sinkevičius' return as mayor of Jonava.
