Berger was born in Czechoslovakia. He became a cartoonist in Prague and studied art in Paris and Berlin. In Berlin, he secured an assignment with one of the largest Berlin daily newspapers and was one of the few journalists admitted to the 1923 Munich trial that followed Hitler's abortive putsch.
Later, when Hitler came to power, Berger's cartoons angered Hitler and Berger was forced to leave the country. After spells in Budapest, Paris, and Geneva, where he attented numerous sessions at the League of Nations, he settled in London in 1935 where he worked for the Daily Telegraph.
During the 1950s, Berger attended many sessions at the United Nations and illustrated virtually every important world leader to be seen at there.
Oscar Berger's works were described by a contemporary as: