The Senate of Pakistan, constitutionally the House of the Federation and commonly the Upper House, is the upper chamber of the bicameral Parliament of Pakistan, with the National Assembly being the lower chamber. It functions as the institutional representative of the Pakistani federating units at the federal level. With a maximum membership of 96, provincial legislatures elect 23 each, using single transferable vote; with four representing the federal capital. Members, referred to as 'senators', sit for six year-terms, with half of the house up for election every three years. Unlike the National Assembly, the Senate is a continuing chamber and hence not subject to dissolution.

First convened in 1973, the Senate's composition and powers are established by the Article 59 of the Constitution of Pakistan. Each of the four provinces is represented by 23 senators regardless of population, while the Islamabad Capital Territory is represented by four senators, all of whom serve staggered six-year terms. The Senate secretariat is located in the east wing of the Parliament Building; the National Assembly convenes in the west wing of the same building.

The Senate has several exclusive powers not granted to the National Assembly, including the powers of making parliamentary bills as a being enforced into law.^{[clarification needed]} Elections are held every three years for one half of the Senate and each Senator has a term of six years. The Constitution does not allow for the dissolution of the Senate.

After Independence, the first Constituent Assembly of Pakistan, elected in December 1947 after partition, was assigned the task of framing the Constitution of Pakistan. This Assembly passed the Objectives Resolution on 12 March 1949, laying down principles which later became a substantive part of the Constitution of Pakistan. However, before it could accomplish the task of framing the constitution, it was dissolved in October 1954. Thereafter, the Governor General, convened the Second Constituent Assembly in May 1955, which framed and passed the first Constitution of Pakistan on 29 February 1956. That Constitution was promulgated on 23 March 1956, which provided for a parliamentary form of Government with a unicameral legislature. Hence, from 14 August 1947 to 1 March 1956, the Government of India Act 1935 was retained as the Constitution of Pakistan.

On October 7, 1958, Martial Law was promulgated and the Constitution abrogated. The Military Government appointed a Constitution Commission in February 1960 which framed the 1962 Constitution. That Constitution provided for a Presidential form of Government with a unicameral legislature. The 1962 Constitution was abrogated on 25 March 1969. The Civil Government, which came to power in December 1971 pursuant to 1970 elections, gave the nation an interim Constitution in the year 1972.

The 1970 Assembly framed the 1973 Constitution, which was unanimously passed on 12 April and promulgated on 14 August 1973. The 1973 Constitution provides for a parliamentary form of Government with a bicameral legislature, comprising the National Assembly and the Senate.

The membership of the Senate, which was originally 45, was raised to 63 in 1977 and to 87 in 1985. The government of Gen. Pervez Musharraf raised the membership of the Senate from 87 to 100 through the Legal Framework Order (LFO), 2002, enforced on 21 August 2002 and the government of Asif Ali Zardari raised the membership of the Senate from 100 to 104 through the 18th amendment in 2011 (four minority members from four provinces). After the Twenty-Fifth Amendment, the number of seats in the Senate was reduced to 96, as the seats for FATA were removed after its merger with KPK.

The main purpose for the creation of the Senate of Pakistan was to give equal representation to all the federating units since the membership of the National Assembly was based on the population of each province. Equal provincial membership in the Senate, thus, balances the provincial inequality in the National Assembly.