Henry Seriake Dickson was born on 28 January 1966 in Toru-Orua, Sagbama Local Government Area of Bayelsa State. He joined the Nigeria Police Force in 1986, studied law at the Rivers State University of Science and Technology, graduating in 1992, and was called to the Nigerian Bar in 1993.
He founded the law firm Seriake Dickson & Co. in Port Harcourt, later Yenagoa, and was its managing solicitor from 1996 to 2006. He was the pioneer publicity secretary of the Nigerian Bar Association, Yenagoa branch, from 1996 to 1998. In the Alliance for Democracy he was Bayelsa State chairman from 1998 to 2000 and national legal adviser from 2000 to 2002.
He was appointed Attorney General and Commissioner for Justice of Bayelsa State in 2006, under Governor Goodluck Jonathan. Elected to the House of Representatives in 2007, he chaired the House Committee on Justice and later the Committee on Special Duties, and sponsored or co-sponsored bills on party democracy, freedom of information, anti-corruption and constitutional reform.
He was sworn in as the 11th Governor of Bayelsa State on 14 February 2012 and served two terms, to 14 February 2020. He won the Bayelsa West senatorial bye-election in December 2020, was re-elected in February 2023, and has chaired the Senate Committee on Ecology and Climate Change since August 2023.
He was made a Commander of the Order of the Niger (CON) on 28 May 2023. In February 2026, INEC registered the Nigeria Democratic Congress, the party he founded.