The last Nevada governor before term limits, who was eligible for an elected third term, O'Callaghan chose not to run again in 1978. After he left office O'Callaghan became the executive editor of the "Las Vegas Sun", a job he held until his death in 2004. He was also the publisher of the "Henderson Home News" and "Boulder City News". In the 1990s, O'Callaghan monitored elections in Nicaragua and northern Iraq, and was a strong supporter of the country of Israel.