Sir John Hullock (3 April 1767 – 31 July 1829) was an English lawyer and judge, a baron of the exchequer.
With James Scarlett, John Cross and Joseph Littledale he conducted the prosecution on behalf of the Crown against Henry Hunt and his associates at Manchester in March 1820.
In July of the same year he took part in the proceedings against John Baird and Andrew Hardie at Stirling.
Hullock advised Sir William Rae on English law; this was in spite of the objection of Francis Jeffrey, for the defence, that he was not qualified to appear.
After holding the office of judge for little more than six years he fell suddenly ill while on circuit, and, dying at Abingdon on 31 July 1829, aged 65, was buried in the family vault at Barnard Castle.