The Seimas of the Republic of Lithuania, or simply the Seimas, is the unicameral legislative body of the Republic of Lithuania. The Seimas constitutes the legislative branch of government in Lithuania, enacting laws and amendments to the Constitution, passing the budget, confirming the Prime Minister and the Government and controlling their activities.

The Government of Lithuania, officially the Government of the Republic of Lithuania, is the cabinet of Lithuania, exercising executive power in the country. Among other responsibilities, it executes laws and resolutions of the parliament, the Seimas, and the decrees of the President, manages state property and, together with the president, executes the foreign policy of the country. The Government also has the right of legislative initiative, puts together the state budget and presents it to the Seimas for approval.