Cornelius Andrew Cadmus (October 7, 1844 – January 20, 1902) was an American Democratic Party politician who represented New Jersey's 5th congressional district for two terms from 1891 to 1895.

After finishing schooling, he engaged in the feed and grain business in Paterson, New Jersey.

He served as a member of the New Jersey General Assembly in 1884 and 1885, as well as Sheriff of Passaic County from 1887 to 1890.

He resumed his former business pursuits while also serving as a member of the board of inspectors of the New Jersey prison.

This article incorporates public domain material from the Biographical Directory of the United States Congress