Maharaja Karam Singh (1798-1845), was the 4th Patialvi ruler of the princely state of Patiala, Born to Rajah Sahib Singh (1773-1813), and Rani Aas Kaur, into a Jatt family of Royal Sidhu clan. He ascended the throne on 30th June 1813 at the age of fifteen, during the battle between the Gurkhas under Amar Singh thapa and the British east India Company. The mother of the new king managed administration for some time.He was married to Bibi Rup Kaur and had 3 daughters.

He was an able ruler. Initially, During his reign he helped the British in preventing Gurkha incursions into the Punjab and in return secured a large tract in the Himalayan foothills. Later in life, During his rule, Patiala faced external threats from neighboring states, particularly in the turbulent period marked by the Anglo-Sikh wars. Karam Singh actively participated in these conflicts, displaying strategic acumen in both alliances and battles. His leadership was crucial during the First Anglo-Sikh War.

During his rule, Patiala faced external threats from neighboring states, particularly in the turbulent period marked by the Anglo-Sikh wars. Karam Singh actively participated in these conflicts, displaying strategic acumen in both alliances and battles. His leadership was crucial during the First Anglo-Sikh War (1845-1846).

He built shrines in honour of the Gurus at many historical sites within his state and outside and moreover, making endowments for their maintenance. Tho his reign was short lived and he died in December, 1845.