Encyclopædia Britannica: Gregory III
- Very brief summary of his pontificate. In the 11th edition (1911).
- http://encyclopedia.jrank.org/GRA_GUI/GREGORY_III.html

Pope Saint Gregory III
- Pious reflection on his election and pontificate. By Terry Matz.
- http://www.catholic.org/saints/saint.php?saint_id=53

The Ecole Glossary: Gregory III
- Brief biography, by Karen Rae Keck.
- http://www2.evansville.edu/ecoleweb/glossary/gregoryiii.html

St. Gregory III
- Short biography by Joseph Brusher.
- http://www.ewtn.com/library/MARY/GREG3.htm

Pope St. Gregory III
- A Syrian, was elected the successor of Pope St. Gregory II by acclamation, d. 741.
- http://www.newadvent.org/cathen/06789a.htm