Hindu–Muslim unity is a religiopolitical concept in the Indian subcontinent which stresses members of the two largest faith groups there, Hindus and Muslims, working together for the common good. The concept was championed by various persons, such as leaders in the Indian independence movement, namely Mahatma Gandhi and Khan Abdul Ghaffar Khan, as well as by political parties and movements in British Raj, such as the Indian National Congress, Khudai Khidmatgar and All India Azad Muslim Conference. Those who opposed the partition of India often adhered to the doctrine of composite nationalism.

In Mughal India, the emperor Akbar advocated for Hindu–Muslim unity, appointing both Hindus and Muslims as officials in his court. Akbar participated and promoted festivals of both Hinduism and Islam. He also created feasts, such as Phool Walon Ki Sair (although this festival is said to have been started much later in the nineteenth century under Akbar II) to be celebrated by citizens of all faiths. During the Mughal era, Indian art and culture thrived, with the construction of grand monuments such as the Taj Mahal and the Red Fort. The Mughals fostered religious harmony and cultural advancements and nurtured Hindu scholars, poets, and artists, facilitating a dynamic cultural interchange that enriched both Islamic and Hindu traditions.

Chhatrapati Shivaji also promoted Hindu–Muslim unity. Maratha Hindavi Swarajya had many Muslims in high posts. Shivaji's personal security, his most trusted courtiers, were Muslims. A Muslim general had led the Maratha troops in the third battle of Panipat and sacrificed for the cause.

Sayyid Jamal al-Din al-Afghani Asadabadi advocated for Hindu–Muslim unity, maintaining that it would help the Indian independence movement in their goal to establish an independent India.

During the 17th to 19th centuries, India was ruled by the British, who introduced a policy of divide and rule to maintain their control over the country. In the Indian Rebellion of 1857, many Hindus and Muslims of India mobilised together to fight against the East India Company. Reflecting on this in 2007, Manmohan Singh stated that these events "stood as a great testimony to the traditions of Hindu–Muslim unity that held out as an example for subsequent generations".

The Lucknow Pact of 1916 was seen as an "important step forward in achieving Hindu–Muslim unity" during the era of the Indian independence movement. Muhammad Ali Jinnah advocated Hindu–Muslim unity in early years of his political career. Gopal Krishna Gokhale stated that Jinnah "has true stuff in him, and that freedom from all sectarian prejudice which will make him the best ambassador of Hindu–Muslim Unity".

Ram Prasad Bismil and Ashfaqulla Khan emphasised the importance of Hindu-Muslim unity for India's progress and independence. Bismil urged Indians to rise above religious and communal divisions, recognising unity as the foundation for building a strong and free nation. His vision highlighted the need for collective harmony to achieve the common goal of liberation and prosperity for all communities. Hindu-Muslim unity and amity were last wishes of Kakori martyrs.

Muslim scholars of the Deoband school of thought, such as Qari Muhammad Tayyib and Kifayatullah Dihlawi, championed Hindu–Muslim unity, composite nationalism, and called for a united India. Maulana Sayyid Hussain Ahmad Madani, the leader of the Jamiat Ulema-e-Hind, stated: