:For the Australian Band, see British India (band).

British Raj (rāj, lit. "reign" in Hindi) or British India, officially the Indian Empire, and internationally and contemporaneously, India, is the term used synonymously for the region , the rule, and the period, from 1858 to 1947, of the British Empire on the Indian subcontinent. The region included areas directly administered by the United Kingdom (contemporaneously, "British India") as well as the princely states ruled by individual rulers under the paramountcy of the British Crown. The princely states, which had all entered into treaty arrangements with the British Crown, were allowed a degree of local autonomy in exchange for accepting protection and complete representation in international affairs by the United Kingdom.

The British Indian Empire included the regions of present-day India, Pakistan, and Bangladesh, and, in addition, at various times, Aden (from 1858 to 1937), Lower Burma (from 1858 to 1937), Upper Burma (from 1886 to 1937), British Somaliland (briefly from 1884 to 1898), and Singapore (briefly from 1858 to 1867). Burma was directly administered by the British Crown from 1937 until its independence in 1948. Among other countries in the region, Ceylon (now Sri Lanka), which was ceded to the United Kingdom in 1802 under the Treaty of Amiens, was a British Crown Colony, but not part of British India. The kingdoms of Nepal and Bhutan, both having fought wars with the British, had subsequently signed treaties with them which recognised them as independent states. The Kingdom of Sikkim was established as a princely state after the Anglo-Sikkimese Treaty of 1861, however, the issue of sovereignty was left undefined. The Maldive Islands were a British protectorate from 1867 to 1965, but not part of British India.

The Indian Empire, which issued its own passports, was commonly referred to as India both in the region and internationally. As India, it was a founding member of the League of Nations, and a member nation of the Summer Olympics in 1900, 1920, 1928, 1932, and 1936.

The system of governance lasted from 1858, when the rule of the British East India Company was transferred to the Crown in the person of Queen Victoria (and who, in 1876, was proclaimed Empress of India), until 1947, when the British Indian Empire was partitioned into two sovereign dominion states, the Union of India (later the Republic of India) and the Dominion of Pakistan (later the Islamic Republic of Pakistan and the People's Republic of Bangladesh).