The Tamil Nadu Legislative Assembly is the unicameral legislature of the Indian state of Tamil Nadu. It has a strength of 234 members, all of whom are democratically elected using the first-past-the-post system. The presiding officer of the Assembly is the Speaker. The term of the Assembly is five years, unless dissolved earlier.

Tamil Nadu Legislative Council was the upper house of the former bicameral legislature of the Indian state of Tamil Nadu. It began its existence as Madras Legislative Council, the first provincial legislature for Madras Presidency. It was initially created as an advisory body in 1861, by the British colonial government. It was established by the Indian Councils Act 1861, enacted in the British parliament in the aftermath of the Indian Rebellion of 1857. Its role and strength were later expanded by the second Council Act of 1892. Limited election was introduced in 1909. The Council became a unicameral legislative body in 1921 and eventually the upper chamber of a bicameral legislature in 1937. After India became independent in 1947, it continued to be the upper chamber of the legislature of Madras State, one of the successor states to the Madras Presidency. It was renamed as the Tamil Nadu Legislative Council when the state was renamed as Tamil Nadu in 1969. The Council was abolished by the M. G. Ramachandran administration on 1 November 1986. In 1989, 1996 and 2010, the DMK regime headed by M. Karunanidhi tried to revive the Council. The former AIADMK regime (2016-2021) expressed its intention not to revive the council and passed a resolution in the Tamil Nadu Legislative Assembly in this regard.