John Johnston (January 22, 1781 – April 20, 1851) was a Scottish-American bookkeeper and merchant who was a co-founder of New York University.

Johnston was born on January 22, 1781, at Barnboard Mill in the Parish of Balmaghie, Gallowayshire, Scotland.

The firm, based at 57 South Street, sold Scotch goods and, later, tobacco from Virginia and wines from Madeira and Italy.

She was a widow of Rhesa Howard Jr., himself a nephew of William Few, signer of the U.S. Constitution from Georgia whose brother-in-law was U.S. Secretary of the Treasury Albert Gallatin.

Together, John and Margaret were the parents of: Johnston, who suffered from gout, died on April 20, 1851, at his residence, 7 Washington Square in New York City.