Punjab is a state in northwestern India. Forming part of the larger Punjab region of the Indian subcontinent, the state is bordered by the Indian states of Himachal Pradesh to the north and northeast, Haryana to the south and southeast, and Rajasthan to the southwest; by the Indian union territories of Jammu and Kashmir to the north and Chandigarh to the east. To the west, it shares an international border with the identically named Pakistani province of Punjab, and as such is sometimes referred to as East Punjab or Indian Punjab for disambiguation purposes.[9] The state covers an area of 50,362 square kilometres (19,445 square miles), which is 1.53% of India's total geographical area,[10] making it the 19th-largest Indian state by area out of 28 Indian states (20th largest, if Union Territories are considered). With over 27 million inhabitants, Punjab is the 16th-largest Indian state by population, comprising 23 districts.[2] Punjabi, written in the Gurmukhi script, is the most widely spoken and the official language of the state.[11] The main ethnic group are the Punjabis, with Sikhs (57.7%) and Hindus (38.5%) forming the dominant religious groups.[12] The state capital, Chandigarh, is a union territory and also the capital of the neighbouring state of Haryana. Three tributaries of the Indus River — the Sutlej, Beas, and Ravi — flow through Punjab.

The history of Punjab has witnessed the migration and settlement of different tribes of people with different cultures and ideas, forming a civilisational melting pot. The ancient Indus Valley Civilisation flourished in the region until its decline around 1900 BCE.[14] Punjab was enriched during the height of the Vedic period, but declined in predominance with the rise of the Mahajanapadas.[15] The region formed the frontier of initial empires during antiquity including Alexander's and the Maurya empires.[16][17] It was subsequently conquered by the Kushan Empire, Gupta Empire,[18] and then Harsha's Empire.[19] Punjab continued to be settled by nomadic people; including the Huna, Turkic and the Mongols. Punjab came under Muslim rule c. 1000 CE,[20] and was part of the Delhi Sultanate and the Mughal Empire.[21] Sikhism, based on the teachings of Sikh Gurus, emerged between the 15th and 17th centuries. Conflicts between the Mughals and the later Sikh Gurus precipitated a militarisation of the Sikhs, resulting in the formation of a confederacy after the weakening of the Mughal Empire, which competed for control with the larger Durrani Empire.[22] This confederacy was united in 1801 by Maharaja Ranjit Singh, forming the Sikh Empire.

The larger Punjab region was annexed by the British East India Company from the Sikh Empire in 1849.[24] At the time of the independence of India from British rule in 1947, the Punjab province was partitioned along religious lines amidst widespread violence, with the Muslim-majority western portion becoming part of Pakistan and the Hindu- and Sikh-majority east remaining in India, causing a large-scale migration between the two.[25] After the Punjabi Suba movement, Indian Punjab was reorganised on the basis of language in 1966,[26] when its Haryanvi- and Hindi-speaking areas were carved out as Haryana, Pahari-speaking regions attached to Himachal Pradesh and the remaining, mostly Punjabi-speaking areas became the current state of Punjab. A separatist insurgency occurred in the state during the 1980s.[27] At present, the economy of Punjab is the 15th-largest state economy in India with ₹8.02 trillion (US$94 billion) in gross domestic product and a per capita GDP of ₹264,000 (US$3,100), ranking 17th among Indian states.[4] Since independence, Punjab is predominantly an agrarian society. It is the ninth-highest ranking among Indian states in human development index.[5] Punjab has bustling tourism, music, culinary, and film industries.