Robert Mullen may refer to:
Robert Mullen (Nevada politician) (fl. 1868–1872), member of the Nevada Senate Robert S. Mullen (1884–1959), American lawyer and politician from New York Robert R. Mullen, founder of public relations company Robert Mullen Company
See also Robert N. Mullin (1893–1982), writer of Western history Robert Mullan (1947–2024), British film director, writer and producer