Born New Year's Day, 1817, at Oakley House in Bedfordshire. He was the son of Captain Godschall Johnson (1780–1859), formerly of the 10th Royal Hussars, and his wife Lucy (died 1823), daughter of Sir Cecil Bishopp (1753–1828) 8th Bt., of Parham Park, West Sussex; 12th Baron Zouche. He was a nephew of Colonel Cecil Bisshopp. Francis Johnson was educated at Harrow and afterwards at Saint-Omer and Bruges. In his early life he had the reputation of an excellent athlete, and in later life he was remembered as a renowned wit.