Moldavia and Wallachia, while remaining under the suzerainty of the Ottomans, were recognized as quasi-independent self-governing principalities under the protection of the other European Powers.

The Paris Convention of 19 August 1858 promulgated Statutul Dezvoltător ("Expanding Statute"), to introduce a bicameral parliament, with an upper house named in Romanian Corpul Ponderator ("Moderating Body").

The 1923 Constitution, approved by both houses of parliament in May 1923, again entrusted legislative power to the Senate, the Assembly of Deputies, and the King.

In February 1938, amid the political crisis which soon led to the Second World War, King Carol II imposed a more authoritarian monarchy.

After the royal coup of 23 August 1944, on 15 July 1946 the government controlled by the Romanian Communist Party (PCR) issued an electoral law that re-organized the parliament as a single legislative body, called the Assembly of Deputies, thus disestablishing the Senate.

Under the 1948 constitution this became the Great National Assembly, a relatively impotent body subordinate to the power of the Romanian Communist Party (PCR).

Under the country's new post-communist Constitution of 1991, approved by a national referendum in 1991, Romania returned to a bicameral parliamentary system, in which the Senate is an elected body.

A referendum on modifying the size and structure of the Parliament from the current bicameral one with 137 senators and 334 deputies to a unicameral one with a maximum of 300 seats was held on 22 November 2009, at the same time as the first round of the 2009 presidential election.

The electors approved by a percentage of 77.78% (50.95% turnout) the adoption of a unicameral Parliament, however as of 2025 the necessary constitutional changes to achieve this have not been put into effect.

Between 1929 and 1940, it was temporarily housed in a building on the Regina Elisabeta Boulevard, while a new Palace of the Senate was to be built in today's Națiunile Unite Square.