The Riigikogu is the unicameral parliament of Estonia. In addition to approving legislation, the Parliament appoints high officials, including the prime minister and chief justice of the Supreme Court, and elects the president. Among its other tasks, the Riigikogu also ratifies significant foreign treaties that impose military and proprietary obligations and bring about changes in law, as well as approves the budget presented by the government as law, and monitors the executive power.

The prime minister of Estonia is the head of government of the Republic of Estonia. The prime minister is nominated by the president after appropriate consultations with the parliamentary factions and confirmed by the parliament (Riigikogu). In case of disagreement, the parliament can reject the president's nomination and choose their own candidate. In practice, since the prime minister must maintain the confidence of parliament in order to remain in office, they are usually the leader of the senior partner in the governing coalition. The current prime minister is Kaja Kallas of the Reform Party. She took the office on 26 January 2021 following the resignation of Jüri Ratas.