Sir John Simon (9 December 1818 – 24 June 1897) was a British sergeant at law and Liberal Party politician.
Simon was born at Montego Bay Jamaica, the son of Isaac Simon. He was sent to England in 1833 to a school in Liverpool. He also studied Hebrew as he wanted to become a rabbi, but he entered the law instead. He graduated from the University of London in 1841 and was called to the bar at the Middle Temple in 1842. He went to Jamaica after his marriage in 1843 and practised law at Spanish Town until 1843 when he returned to England for his wife's health. He became a successful on the northern circuit, and in the superior courts in London and in 1864 he was created a sergeant at law. He was frequently a judge in Manchester and Liverpool, and at the City of London Court. He became QC in 1968. Simon was elected as MP for Dewsbury in 1868 and held the seat until he retired through ill health in 1888. In parliament he was particularly concerned with reforms of the judicature, and outside parliament was active in campaigning on behalf of Russian Jews.