Margáin Gleason ((1913-02-13)13 February 1913 – (1997-09-11)11 September 1997) was a Mexican economist, politician and diplomat who served as Secretary of Finance in the cabinet of Luis Echeverría (1970–73), as ambassador of Mexico to the United States (1964–70 and 1976–82), as ambassador of Mexico to the United Kingdom (1973–76) and as senator representing the Institutional Revolutionary Party (PRI, 1982–88).