Henri Thomas was born at Anglemont, Vosges, and grew up in the Alsace/Lorraine region of France.
He moved to Paris to attend the prestigious Henri IV high school, working with the noted essayist Alain.
He mixed with many influential intellectuals and writers in Paris in the 1930s and 1940s, most notably Gide and Paulhan.
In the 1940s he did his military service, got married, worked on a number of literary reviews and separated from his wife.
In 1958, he was hired as a professor at Brandeis University in the United States, where he lived and worked for two years.