Robert Nicols Martin (14 January 1798-20 July 1870) was a member of the US House of Representatives (NR-MD 8) from 4 March 1825 to 3 March 1827, succeeding John S. Spence and preceding Ephraim King Wilson. Born in Cambridge, Maryland, he practiced law before serving in Congress and resuming the practice of law in Baltimore, occasionally serving as a judge.