For All the Saints
- Biographical essay on Pope St. Sylvester I.
- http://www.saintpatrickdc.org/ss/1231.htm#sylv

The Ecole Glossary
- Brief biography of Pope St. Sylvester I, by Karen Rae Keck.
- http://www2.evansville.edu/ecoleweb/glossary/sylvesteri.html

Lives of the Saints
- St. Sylvester, Pope, Confessor. From Alban Butler's Lives of the Saints.
- http://www.ewtn.com/library/MARY/SYLVESTR.HTM

Popes Through the Ages
- Short biography of Pope St. Sylvester I, from the book by Joseph Brusher.
- http://www.cfpeople.org/Books/Pope/POPEp33.htm

James Kiefer's Christian Biographies
- Sylvester of Rome, bishop. With prayer in traditional (Anglican) and contemporary language.
- http://elvis.rowan.edu/~kilroy/JEK/12/31.html

Catholic Encyclopedia
- Pope St. Sylvester I, in office for 21 years, while Constantine was emperor. St. Sylvester died in 335.
- http://www.newadvent.org/cathen/14370a.htm