John McMullin (October 18, 1765September 12, 1843) was an American silversmith, active in Philadelphia.
McMullin was born in Philadelphia. He worked in circa 17951810 as an individual silversmith and jeweler, then from 1811 to 1815 in a series of partnerships (1811-1813 with James Black as McMULLIN & BLACK, 18131814 with James McMullin, 18141815 with William Seal as SEAL & MCMULLIN) and finally on his own again from 18151841 as a silversmith and jeweler. During the French Revolution, he took in the Delormerie family and paid for Adelaide Celestis Delormerie's memorial when she died at the age of 16. McElroy's 1830 directory lists his address as 114 South Front Street. He died in Philadelphia, where he is buried in the Woodlands Cemetery. His work is collected in the Cincinnati Art Museum, the Metropolitan Museum of Art and, perhaps, the Museum of Early Southern Decorative Arts.