Gunnel Vallquist was born in Stockholm and was the daughter of a lieutenant-colonel. She graduated in philosophy from Uppsala University in 1946, received an honorary doctorate of theology from Lund University in 1976, and became a professor in 1981. She was a literary critic for papers such as Svenska Dagbladet and Bonniers Litterära Magasin, lived in Rome for a number of periods and in Paris for twelve years. Since 1982, she has been a member of Svenska Akademien (The Swedish Academy).
As a Catholic, she has published books and essays primarily on religious issues. However, she is best known for her translation of Marcel Proust's À la recherche du temps perdu into Swedish.