João Hugo Eduardo de Sequeira (20 April 1915 – 17 October 1989), popularly known as Dr. Jack de Sequeira; also known as Jak Siker according to local naming conventions, was a prominent Goan politician and is widely considered in Goa to be the Father of the Opinion Poll, which led to the former territory attaining statehood in 1987. He was Goa's first Leader of the Opposition when the Legislative Assembly was launched in 1963. He was born in Burma, of Goan parents, and shaped politics in Goa during the 1960s and 1970s in particular.