The Letters of George Santayana Book One
- Michael Hodges reviews this book together with the fith volume of The Works of George Santayana. From Notre Dame Philosophical Reviews.
- http://ndpr.nd.edu/review.cfm?id=1286

Columbia Encyclopedia: Santayana, George
- Life, philosophy, and bibliography.
- http://www.bartleby.com/65/sn/Sntyan.html

University of Waterloo - Overheard in Seville: Bulletin of the Santayana Society
- Journal dedicated to the study of Santayana's life and work. Includes tables of contents, PDF files of many articles.
- http://www.math.uwaterloo.ca/~kerrlaws/Santayana/Bulletin/seville.html

MSN Learning & Research: Santayana, George
- Short biography.
- http://encarta.msn.com/encnet/refpages/RefArticle.aspx?refid=761560883

Stanford University - George Santayana
- Entry in the Stanford Encyclopedia by Herman Saatkamp.
- http://plato.stanford.edu/entries/santayana/

The Critical Edition of Works by George Santayana
- Collecting and publishing a critical edition of the works, edited by Herman J. Saatkamp Jr.
- http://www.iupui.edu/~santedit/

Jorge Agustín Nicolás de Santayana
- Article and bibliography at the Books and Writers website.
- http://www.kirjasto.sci.fi/santayan.htm