John O'Leary (January 16, 1947 – April 2, 2005) served as mayor of Portland, Maine, and as United States ambassador to Chile under President Bill Clinton.
He later attended Clare College, Cambridge University, on a Mellon fellowship and received a master's degree in 1971.
he died of motor neurone disease in DC in April 2005 at 58 He served as a member of the Portland City Council 1975-82) and for a term as that city's largely ceremonial Mayor (1980–81).
He ran unsuccessful candidate for the U.S. House from Maine's First Congressional District in 1982, losing in the Democratic primary.
[2] O'Leary served as the United States Ambassador to Chile from 1998 to 2001.