Udham Singh (26 December 1899 – 31 July 1940) was an Indian revolutionary best known for assassinating Sir Michael O'Dwyer, the former Lieutenant Governor of the Punjab in British India, on 13 March 1940. The assassination has been described as an avenging of the Jallianwala Bagh massacre in Amritsar in 1919. 
Udham Singh is a well-known figure of the Indian independence movement. He is sometimes referred to as Shaheed-i-Azam Sardar Udham Singh (the expression "Shaheed-i-Azam," Urdu: شهید اعظم, means "the great martyr"). A district (Udham Singh Nagar) of Uttarakhand was named after him in October 1995 by Mayawati government.
