Maharaja Sir Hari Singh, GCSI, GCIE, GCVO (30 September 1895, Jammu-26 April 1961, Mumbai) was the last ruling Maharaja of the princely state of Jammu and Kashmir in India.

Singh was hostile towards the Congress, in part because of the close friendship between Kashmiri political activist and socialist Sheikh Abdullah and Nehru. He also opposed the Muslim League and its members' communalist outlook illustrated in their two-nation theory.

In 1947, Singh chose to accede his kingdom to India, although a majority of the kingdom's population was Muslim. Pakistan and India fought several wars over possession of the state.

He married Maharani Tara Devi (1910-1967), his fourth wife as his first three wives had died young , and had one son, Karan Singh.

Hari Singh (1910 - 2003) was the Inspector General of Forests of India in the 1960s. In 1966 he was responsible for the creation of the Indian Forest Service to cater to the need for inter-state coordination and uniformity of approach in dealing with the scientific management of forests and the environment. The Indian Forest Service was the third all-India service to be created, the others being the Indian Administrative Service and the Indian Police Service.

Having studied forestry at the Edinburgh, he joined the Bombay Presidency as a Forest Officer and set a new direction to forest management in the state. He later served as chief conservator of forests of Gujarat. Heading the Forest Department at the Centre, he is credited not only with constituting the Indian Forest service but also introducing the concept of "social forestry" in India, a policy to preserve the greenery of the area, provide firewood, prevent soil erosion as well as consolidation of unmade road shoulders. In India today there is a major wing of the Forest Department focussing on social forestry.

Hari Singh is also credited with a seminal study on the tribals of "BUSTER", the original tribal formation in central India.

He was the forestry member in the Second National Commission on Agriculture, where he introduced the idea of corporatization of several forestry functions like the Forest Plantation Corporation and Forest Industries Corporation so as to raise resources for forestry.

Hari Singh AVSM (October 24, 1922 - March 14, 2003) was a Brigadier in the Indian Army who played a significant role in the Indo-Pakistani War of 1965. He was awarded the Ati Vishisht Seva Medal by the President of India for rendering distinguished service of an exceptional order.

Hari Singh is a marathon runner from India.

He placed placing 42nd among 67 entrants with a time of of 2:34:20 in the 1987 World Championships in Athletics Men's Marathon.