He was born into a royal Punjabi Jat Sikh family of the Sidhu clan to parents Maharaja Sir Yadavindra Singh and Maharani Mohinder Kaur of Patiala.

[16] Singh was inducted into the Indian National Congress (INC) by Rajiv Gandhi, his friend from school and who later became Prime Minister of India, and was first elected to the Lok Sabha in 1980.

[9][19] Singh has been a member of the Punjab Vidhan Sabha for five terms representing Patiala (Urban) thrice, Samana and Talwandi Sabo once each.

[21] In September 2008, a special committee of Punjab Vidhan Sabha, during the tenure of a government led by Akali Dal-Bharatiya Janata Party, expelled him on the count of regularities in the transfer of land related to the Amritsar Improvement Trust.

[22] He defeated senior Bharatiya Janata Party leader Arun Jaitley by a margin of 102,770 votes in 2014 general elections from Amritsar seat.

[36] Singh's party PLC lost election deposit in all but one of the 28 seats it had contested with garnering 0.54% of the total votes polled.

[35] During the 2024 Indian General Election, Singh was absent from the BJP's electoral campaigns in Punjab due to health related reasons.

[38] In October 2024, after a one and a half year absence from active politics, Singh made a public visit to the grain market in Khanna.

[39] In November 2024, Singh criticised Prime Minister of Canada Justin Trudeau, stating that his support for Khalistan movement separatists in Candna led to the deterioration in India-Canada relations.

[44] His wife, Preneet Kaur, served as a Member of Parliament and was Minister of State in the Ministry of External Affairs from 2009 to 2012.

[45] His elder sister Heminder Kaur is married to former Minister of External Affairs K. Natwar Singh.

[46] He is also related to Shiromani Akali Dal (A) leader and former Indian Police Service officer Simranjit Singh Mann.