The Grand National Assembly of Turkey (Turkish: Türkiye Büyük Millet Meclisi [tyɾcije byjyc milːet medʒlisi]), usually referred to simply as the GNAT or TBMM, also referred to as Parlamento (lit. 'Parliament' in Turkish), is the unicameral Turkish legislature. It is the sole body given the legislative prerogatives by the Turkish Constitution. It was founded in Ankara on 23 April 1920 amid the National Campaign. This constitution had founded its pre-government known as 1st Executive Ministers of Turkey (Commitment Deputy Committee) in May 1920. The parliament was fundamental in the efforts of Mareşal Mustafa Kemal Atatürk, 1st President of the Republic of Turkey, and his colleagues to found a new government out of the remnants of the Ottoman Empire.

There are 600 members of parliament (deputies) who are elected for a five-year term by the D'Hondt method, a party-list proportional representation system, from 87 electoral districts which represent the 81 administrative provinces of Turkey (Istanbul and Ankara are divided into three electoral districts whereas İzmir and Bursa are divided into two each because of its large populations). To avoid a hung parliament and its excessive political fragmentation, from 1982 to 2022, a party must have won at least 10% of the national vote to qualify for representation in the parliament, but in 2022 this was reduced to 7%. As a result of the 10% threshold, only two parties won seats in the legislature after the 2002 elections and three in 2007. The 2002 elections saw every party represented in the previous parliament ejected from the chamber and parties representing 46.3% of the voter turnout were excluded from being represented in parliament. This threshold has been criticized, but a complaint with the European Court for Human Rights was turned down.

Independent candidates may also run and can be elected without needing a threshold.

A new term in the parliament began on 2 June 2023, after the 2023 general election. Devlet Bahçeli MHP temporarily served as the speaker, as it is customary for the oldest member of the TBMM to serve as speaker during a hung parliament. Numan Kurtulmuş was elected after the snap elections on 7 June 2023.

The parliament's minutes are translated into the four languages: Arabic, Russian, English and French, but not in the Kurdish language which is the second most spoken native language in Turkey. Though phrases in the Kurdish language can be permitted, whole speeches remain forbidden.

Parties who have at least 20 deputies may form a parliamentary group. Currently there are six parliamentary groups at the GNAT: AK Party, which has the highest number of seats, CHP, MHP, Good Party, DEM, and New Path.

These committees are one of auditing tools of the Parliament. The research can begin upon the demand of the Government, political party groups or min 20 MPs. The duty is assigned to a committee whose number of members, duration of work and location of work is determined by the proposal of the Parliamentary Speaker and the approval of the General Assembly.

These committees are established if any investigation demand re the president, vice president, and ministers occur and approved by the General Assembly through hidden voting.