The Greek Senate (Greek: Γερουσία, Gerousia) was the upper chamber of the parliament in Greece, extant several times in the country's history.
During the early stages of the Greek War of Independence, prior to the establishment of a centralized administration, a number of regional councils were established, most of which were termed "senate", but which were unicameral bodies: the Senate of Western Continental Greece, the Areopagus of Eastern Continental Greece (sometimes referred to as "senate"), and the Peloponnesian Senate.
A unicameral body with purely advisory functions, the Senate was established in 1829 by the Fourth National Assembly at Argos in replacement of the Panellinion, established the previous year. It had 27 members, 21 of whom were chosen by the Governor (Ioannis Kapodistrias) from 63 candidates nominated by the Assembly, and further six who were appointed directly by the Governor. Georgios Sisinis was elected as its president. After Kapodistrias' murder in 1831, the Senate appointed a series of governing councils to lead the state. In 1832, the Fifth National Assembly at Nafplion abolished the Senate, but the Senate refused to recognize the act, and survived until the arrival of King Otto in February 1833.
The Senate as an upper chamber was established by the Greek Constitution of 1844. The Senate had 27 members, appointed for life by the King, who in addition could appoint further members up to one half of the statutory number. The Senate, seen as a reactionary body and essentially dependent upon the King, was abolished by the Greek Constitution of 1864.