Karl Gruber (3 May 1909 in Innsbruck – 1 February 1995 in Innsbruck) was an Austrian politician and diplomat. During World War II, he was working for a German firm in Berlin. After the war, in 1945 he became Landeshauptmann of Tyrol for a short time. He then became Foreign Minister of Austria until 1953.
Karl Gruber served as Austrian ambassador to the United States from 1954 to 1957 and from 1969 to 1972, as ambassador to Spain from 1961 to 1966, as ambassador to the Federal Republic of Germany in 1966, and as ambassador to Switzerland from 1972 to 1974.