The Constitution is based on principles of the Westminster system of responsible government, as modified due to Victoria being a state within a federation of Australia.

The original Constitution of Victoria was drafted and approved in Melbourne in March 1854 by the first Victorian Legislative Council, and sent to the United Kingdom for assent.

It was received in London in May 1854 and, after some opposition and delay,[7] was approved (with some amendments) as an Act of the British Parliament in 1855.

Changes have included parliamentary membership numbers, voter eligibility, payment of members, voting methods, size of the ministry, electorate numbers and the powers and responsibilities of the Legislative Council and the Legislative Assembly, besides other matters.

[13] The 2003 amendments also provided for fixed-four year terms for both Houses, election of the Legislative Council by proportional representation, removal of the council's power to block a supply bill (the budget) and a dispute resolution process for bills for which agreement between the houses cannot be reached.