Ahead of his swearing-in ceremony, Nauseda with his wife visited the monument to the nation's patriarch Jonas Basanavicius in the morning.
Later on, he was sworn in during a solemn parliament sitting and then observed a military line-up in the Independence Square outside the Seimas and a parade on Gediminas Avenue from the Seimas to the Cathedral Square.
A service at Vilnius cathedral followed after that.
In the afternoon, a ceremony of the handover of the Presidential Palace took place, and then the government returned its power to the new president.
A concert will take place in Simonas Daukantas Square outside the Presidential Palace in the evening, and an inaugural reception will be held in the courtyard of the President Palace.
Nauseda replaced Dalia Grybauskaite who served as Lithuania's president two terms from 2009.
As an independent candidate, Nauseda was elected Lithuania's president on May 26, receiving 66 percent of votes.