Dilke was appointed one of the five royal commissioners for the Great Exhibition of 1862. Soon after the death of the prince consort he was created a baronet, of Sloane Street in the County of Middlesex. In 1865 he entered parliament as member for Wallingford, a seat he held until 1868. In 1869 he was sent to Russia as representative of England at the horticultural exhibition held at St Petersburg. His health, however, had been for some time failing, and he died suddenly in that city, on 10 May 1869. A selection from his writings, "Papers of a Critic" (2 vols., 1875), contains a biographical sketch by his eldest son Charles.