Ullaskar Dutta was an Indian revolutionary associated with Anushilan Samiti and Jugantar of Bengal, and was a close associate of Barindra Ghosh. He was the principal bomb maker of the Jugantar group until Hemchandra Kanungo returned from Paris learning political theory and explosive chemistry.

Jugantar or Yugantar was one of the two main secret revolutionary trends operating in Bengal for Indian independence. This association, like Anushilan Samiti, started in the guise of a suburban health and fitness club while secretly nurturing revolutionaries. Several Jugantar members were arrested, hanged, or deported for life to the Cellular Jail in Andaman and many of them joined the Communist Consolidation in the Cellular Jail.