The Secretary of State for the Southern Department was a position in the cabinet of the government of the Kingdom of Great Britain up to 1782, when the Southern Department became the Home Office.

Sir Edward Nicholas was an English officeholder and politician who served as Secretary of State to Charles I and Charles II. He also sat in the House of Commons at various times between 1621 and 1629. He served as secretary to Edward la Zouche and the Duke of Buckingham in the Admiralty and became a clerk of the Privy Council. He supported the Royalist cause in the English Civil War and accompanied the court into exile, before assuming the post of Secretary of State on the Restoration.