Martin John O'Connor was an American prelate of the Roman Catholic Church. He served as rector of the Pontifical North American College from 1946–1964 and president of the Pontifical Council for Social Communications from 1948–1971.

The Pontifical North American College (NAC) is a Roman Catholic educational institution in Rome, Italy, that prepares seminarians to become priests in the United States and elsewhere. The NAC also provides a residence for priests who are pursuing graduate work at other pontifical universities in Rome. The NAC also has a continuing education program for veteran priests.