As his entertainment career ebbed, Mr. Gavin became increasingly involved in inter-American political affairs. In the 1960s and early ′70s, he was a special adviser to the secretary general of the Organization of American States, which fosters democracy and regional security. He also undertook assignments promoting American and Latin American film production for the Alliance for Progress, established by President John F. Kennedy.
Mr. Gavin was president of the Screen Actors Guild from 1971 to 1973.
He was named ambassador to Mexico when Ronald Reagan, a like-minded conservative Republican who had also been president of the actors guild, entered the White House in 1981. Mr. Gavin had been active in Reagan’s 1980 presidential campaign.
Amid complaints from veteran diplomats that American embassies were still being turned over to financial backers and unqualified amateurs, the selection of an actor and friend of the president for one of the nation’s most sensitive diplomatic posts was met with dismay in Mexico. Officials there sardonically jested about sending the comedian Cantinflas to Washington in retaliation.
Mr. Gavin was chiefly known in Mexico at the time as the tuxedoed spokesman for Bacardi rum in television commercials. He had some qualifications for the assignment, however. His mother was Mexican, he spoke fluent Spanish, he had extensive travel and business experience in Latin America and he had a degree in Latin American economic history from Stanford University.
But his tenure as ambassador in Mexico City, in charge of an embassy with more than 1,100 American and Mexican employees, became extremely contentious, despite a close relationship between President Reagan and President José López Portillo and his successor, Miguel de la Madrid.
Mr. Gavin pressed Mexico to limit the flow of illicit drugs and illegal immigrants into the United States, and voiced Washington’s belief that the revolutionary Sandinista government in Nicaragua posed dangers to the security of Mexico and Central America. Mexico was cool to many of Washington’s concerns, even when Mr. Gavin relayed intelligence that implicated Mexican officials in corrupt activities.
The ambassador feuded regularly with the Mexican press. Journalists who tracked his movements called him an absentee envoy who had been out of Mexico for 142 of his first 438 days on the job, traveling frequently to Los Angeles. Mr. Gavin insisted that his trips were work-related.
Mr. Gavin was denounced by Mexican business and labor leaders, politicians and academics after he appeared in a 1982 ABC television special, “Mexico: Times of Crisis,” in which he spoke of fears that Central America’s economic and political troubles could “spill over” into Mexico. President López Portillo did not comment, but there were wide demands for Mr. Gavin to resign or be declared persona non grata.
In 1984, after Mr. Gavin had a casual lunch with leaders of the opposition National Action Party, the head of the ruling Institutional Revolutionary Party, which had long controlled political life in Mexico, accused him of interfering in Mexican politics and of insensitivity to Mexican traditions.
And Mr. Gavin sometimes put his foot in his mouth. In 1985, after earthquakes toppled buildings and killed thousands in Mexico, he told reporters “we have been extremely fortunate” that more Americans had not been killed or injured, a circumstance he explained by saying, “The types of hotels that fell down were not the types normally frequented by citizens of the United States.”
Mr. Gavin quietly resigned in 1986 and went on to a successful business career. In retrospect, American business executives gave him high marks for fostering trade, and he was credited with helping Mexican businesses obtain foreign loans as the economy worsened.
He was born John Anthony Golenor in Los Angeles on April 8, 1931, to Herald and Delia Diana Pablos. His father was descended from early Irish landowners in California, his mother from an influential family in Sonora, Mexico. He attended St. John’s Military Academy in Los Angeles and Villanova Preparatory School in Ojai, and graduated from Stanford in 1952.
In the Navy over the next three years, he served as an intelligence officer aboard the aircraft carrier Princeton in the Korean War theater and was an aide to Adm. Milton E. Miles in the Panama Canal Zone.
After his ambassadorship, Mr. Gavin joined the Atlantic Richfield Company as a public relations executive. In 1987 he became president of Univisa Satellite Communications, which at the time was the parent of the Spanish-language television network Univision. He later became a director of various capital investment and financial consulting companies.
He married the actress Cicely Evans in 1957. They had two children, Cristina and Maria, and were divorced in 1965. He had been married to Ms. Towers since 1974. She had two children from a previous marriage, Michael and Maureen McGrath.
Besides Ms. Towers, his survivors include his children and stepchildren and several grandchildren.