Biography.com: John of Salisbury: Concise paragraph on the life of this medieval clergyman.
Catholic Encyclopedia: John of Salisbury: Article on his life and thought by P. Coffey.
Columbia Encyclopedia: John of Salisbury: Concise entry on this medieval scholar, from the 2001 edition.
English Scholars of Paris: John of Salisbury: Section from the Cambridge History of English and American Literature, covering his life and work in some detail.
The Ecole Glossary: John of Salisbury: Concise entry on this thinker, with links to related topics. By Karen Rae Keck.