Bhupinder Singh was born at the Moti Bagh Palace; Patiala and educated at Aitchison College. At age 9; he succeeded as maharaja of Patiala state upon the death of his father; Maharaja Rajinder Singh; on 9 November 1900. A Council of Regency ruled in his name until he took partial powers shortly before his 18th birthday on 1 October 1909 and was invested with full powers by the Viceroy of India; the 4th Earl of Minto; on 3 November 1910.

He served on the General Staff in France; Belgium; Italy and Palestine in the First World War as an Honorary Lieutenant-Colonel; and was promoted Honorary Major-General in 1918 and Honorary Lieutenant-General in 1931. He represented India at the League of Nations in 1925; and was chancellor of the Indian Chamber of Princes for 10 years between 1926 and 1938; also being a representative at the Round Table Conference. He married many times and had many children by his wives and concubines.