Kaja Kallas is an Estonian politician and the current prime minister of Estonia since 2021, the first woman to serve in the role. The leader of the Reform Party since 2018, she was a member of parliament (Riigikogu) in 2011–2014, and 2019–2021. Kallas was a member of the European Parliament in 2014–2018, representing the Alliance of Liberals and Democrats for Europe. Before her election to Riigikogu, she was a lawyer specialising in European competition law.

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.