Sir James Johnston, PC (29 November 1849 – 13 April 1924) was a unionist politician in Ireland.

Johnston was a company director and was elected to the Belfast Corporation for the Irish Unionist Party.

[1] He was High Sheriff of Belfast in 1912/3,[2] and Lord Mayor of Belfast from 1917 to 1919.

[3] In 1921, he was elected to the Senate of Northern Ireland, but served only three years.

[1] He was a Deputy Speaker of the Senate from 1921 until 1923.