Robert M. Riddle (August 17, 1812 – December 18, 1858) was a newspaperman, postmaster and politician who served as Mayor of Pittsburgh from 1853 to 1854.
He entered the mercantile trade in Pittsburgh in the firm of Riddle and Forsyth, and subsequently engaged in the banking business in Philadelphia.
When his term of office expired, he took over the paper called the Spirit of the Age, and renamed it the Commercial Journal.
He was connected to the paper as editor and proprietor until failing health near the end of his life forced him to retire from it.
[1] With the Whigs in steep decline, he moved to the American (Know Nothing) Party,[3] and was active in pushing an anti-slavery agenda within that organization.