MP Ricardas Juska of the Liberal Movement's political group in the parliament confirmed to BNS that he received a positive test result on Monday.
Juska said he has had no in-person contact with his colleagues after Christmas, meaning that other members of the parliamentary group are not required to self-isolate.
MP Justinas Urbanavicius of the conservative Homeland Union–Lithuanian Christian Democrats told BNS he has tested positive but has not developed any symptoms.
MP Kestutis Mazeika of Lithuanian Farmers and Greens Union said he felt unwell after Christmas and tested positive for the coronavirus.
Social Democratic MP Vilija Targamadze earlier wrote on her Facebook page that she had been hospitalized for COVID-19.
The parliament is switching to teleworking next week. The Board of the Seimas decided on Wednesday to hold the first virtual plenary sitting next Tuesday.