The Indian Army is the land-based branch and largest component of the Indian Armed Forces. The President of India is the Supreme Commander of the Indian Army, and its professional head is the Chief of Army Staff (COAS). The Indian Army was established on 1 April 1895 alongside the long established presidency armies of the East India Company, which too were absorbed into it in 1903. Some princely states maintained their own armies which formed the Imperial Service Troops which, along with the Indian Army formed the land component of the Armed Forces of the Crown of India, responsible for the defence of the Indian Empire. The Imperial Service Troops were merged into the Indian Army after independence. The units and regiments of the Indian Army have diverse histories and have participated in several battles and campaigns around the world, earning many battle and theatre honours before and after Independence.

The Indian Army during British rule, also referred to as the British Indian Army, was the main military force of the British Indian Empire until 1947. It was responsible for the defence of both British India and the princely states, which could also have their own armies. As quoted in the Imperial Gazetteer of India, "The British Government has undertaken to protect the dominions of the Native princes from invasion and even from rebellion within: its army is organized for the defence not merely of British India, but of all possessions under the suzerainty of the King-Emperor." The Indian Army was an important part of the forces of the British Empire, in India and abroad, particularly during the First World War and the Second World War.