Baldev Singh (Punjabi: ਬਲਦੇਵ ਸਿੰਘ,Hindi: बलदेव सिंह) (11 July 1902 – 29 June 1961) was an Indian Sikh political leader, he was an Indian independence movement leader and the first Defence Minister of India. Moreover, he represented the Punjabi Sikh community in the processes of negotiations that resulted in the independence of India, as well as the Partition of India in 1947.

After independence, Baldev Singh was chosen to become the first Minister of Defence, and served in this post during the First Kashmir War between India and Pakistan. He was addressed often with the title of Sardar, which in Punjabi and Hindi means leader or chief.

Baldev Singh was born on 11 July 1902 in the village of Dumna in a Jat family in the Rupar district of Punjab. His father was Sir Indra Singh, a reputed industrialist, and his mother was Nihal Kaur Singh (of village Manpur). He was educated initially at Kainaur and subsequently at the Khalsa College in Amritsar, and began working in his father's firm in the steel industry. He rose to the position of director of the firm. He was married to Hardev Kaur of village Jallanpur in Punjab. They had two sons, Sarjit Singh and Gurdip Singh.

Baldev Singh won an election to the Punjab provincial assembly under the Government of India Act 1935 in 1937, as a candidate of the Panthic Party. He became closely linked with Master Tara Singh and the Shiromani Akali Dal.

When the Cripps Mission arrived in India in 1942 to offer Indians some form of self-government, Baldev Singh was chosen to represent the Sikh community in the talks, which also included the chief Indian political party, the Indian National Congress and Muslim League party. The Mission failed to make any progress.

While the Congress Party launched the Quit India Movement, Baldev Singh and other Sikh leaders did not support it. Singh negotiated an agreement with Sir Sikandar Hyat Khan, the leader of the Unionist Party to form a government in Punjab, and became the provincial Development Minister for a brief time in the summer of 1942.

Baldev Singh was chosen again to represent the Sikh viewpoint to the Cabinet Mission Plan that had arrived to discuss proposals for Indian political independence. Singh reiterated the Sikh view that India should remain a united country with special protections for the rights of religious minorities. Singh also insisted that should partition become inevitable, the division of the Punjab should happen in a way to offer territorial protection to the Sikhs from Muslim domination.

Although Baldev Singh and other Sikhs initially opposed the implementation of the Mission's 16 May scheme, on the grounds that it did not offer any protection to the Sikh community, Baldev Singh joined the new Viceroy's Executive Council, to be headed by Congress leaders Jawaharlal Nehru and Vallabhai Patel as the Sikh member. Singh became the Defence Member, a post erstwhile held by the British Commander in Chief of the Indian Army. However, by early 1947, it was clear that the interim government would not work, owing to the conflict between the Congress Party and the Muslim League.