The former subdivisions of Pakistan are states, provinces and territories which mainly existed between 1947 and 1975 when the current provinces and territories were established. The historic regions have no administrative function today but some remain as historical and cultural legacies. In some cases, the current provinces and territories correspond to the historic regions - for example the province of Punjab includes almost all the territory of the former province of West Punjab.

The origins of most of the historic regions lay in the administrative setup inherited from British India. From 1947 to 1971, Pakistan comprised two wings that were 1600 kilometres apart separated by India. The eastern wing comprised the single province of East Bengal which included the Sylhet District from the former Indian province of Assam. The politically dominant western wing was formed from three Governor's provinces (North-West Frontier Province (NWFP), West Punjab and Sind), one Chief Commissioner's Province (Baluchistan), several princely states and parts of Kashmir. In 1948, the area around Karachi was separated from Sind province to form the Federal Capital Territory. In 1950 the North-West Frontier Province was expanded to include the small states of Amb and Phulra and the name of West Punjab province was changed to Punjab. The Baluchistan States Union was formed in 1952 by the four princely states of southwest Pakistan. Thus, between 1947 and 1955, Pakistan comprised five provinces and one territory:

In the western wing there were also thirteen princely states, one union of states and parts of Kashmir:
Baluchistan States Union (combining Kalat, Kharan, Las Bela and Makran - using flag of Kalat)
Gilgit Agency (part of Kashmir)

Simmering tensions between the eastern and western wings of Pakistan led to the One Unit policy announced by Prime Minister Chaudhry Muhammad Ali. The states and provinces of the western wing were merged in 1955, to become divisions of the new province of West Pakistan with the provincial capital at Lahore. At the same time, East Bengal became the new province of East Pakistan with the provincial capital at Dhaka. West Pakistan annexed the former Omani enclave of Gwadar in 1958 as part of Kalat division. In 1960 the federal government was moved from Karachi to Rawalpindi (provisional capital until Islamabad was completed), whilst the federal legislature moved to Dhaka. The Federal Capital Territory was merged with West Pakistan in 1961 to form the new division of Karachi. In 1963 the Trans-Karakoram Tract was transferred by treaty from Gilgit Agency to China under the proviso that the settlement was subject to the final solution of the Kashmir dispute. Thus from 1955 to 1970, Pakistan comprised two provinces:
East Pakistan & West Pakistan

The One Unit policy was regarded as a rational administrative reform to reduce expenditure and eliminate provincial prejudices. However the military coup of 1958 signalled troubled times for the two-province system as the office of Chief Minister of West Pakistan was abolished by President Ayub Khan to be replaced by Governor's rule. Eventually, in 1970, the province of West Pakistan was dissolved by President Yahya Khan and four new provinces were created along with some changes in Pakistani Kashmir. These provinces combined most of the former provinces and states as follows:

New Province Constituent former subdivisions
Baluchistan Province
Baluchistan Chief Commissioners Province
Baluchistan States Union
Enclave of Gwadar
North-West Frontier Province
Former North-West Frontier Province
States of Amb, Chitral, Dir and Swat
Punjab Province
Former West Punjab Province
State of Bahawalpur
Sindh Province
Former Sind Province
State of Khairpur
Former Federal Capital Territory
Centrally Administered Area
906 km² of former West Punjab Province
Northern Areas
Gilgit Agency

The province of East Pakistan became independent in December 1971 as the new country of Bangladesh. The states of Hunza and Nagar were abolished and their territories merged into the Northern Areas in 1974. The Federally Administered Tribal Areas were formed from parts of the North West Frontier Province districts of Peshawar and Dera Ismail Khan in 1975.
The status of the Islamabad area was changed to a capital territory in 1981. The names of two provinces were slightly modified in 1990 - Baluchistan became Balochistan and Sind became Sindh.