- Christian Cyclopedia - Electronic version of the one volume print resource from Concordia Publishing House of The Lutheran Church-Missouri Synod. Includes history, theology, and biographies from within Lutheranism, general Christianity, and non-Christian beliefs.
- Ilumina - An interactive Bible and Encyclopedia Suite, from Tyndale House Publishers. Features computer animation and virtual-reality tours.
- Spiritual Encyclopedia - Covering the most important topics for all spiritual traditions and paths on the way to god. Includes an explanation of divine words and principles governing the creation.
- Thelemapedia - Explore hundreds of topics in this open source encyclopedia dedicated to the religion of Thelema.
- Early Church Online Encyclopedia - Hypertext encyclopedia of the early Christian Church up to the Reformation.
- Indian Christianity - Provides information/research aids for Christianity in India, through St Thomas Christian Encyclopaedia of India, and the Indian Church History Classics.
- Centennial Encyclopaedia of the African Methodist Episcopal Church - Compiled by Richard R. Wright, Jr. Reference work published in 1916.
- Global Anabaptist Mennonite Encyclopedia Online - Information on Anabaptist-related (Amish, Mennonite, Hutterite, Brethren in Christ) topics, source documents, and history.
- Cyclopaedia of African Methodism - An encyclopedia of the African Methodist Episcopal Church, published in 1882.
- World Christian Database - Statistical information on world religions, Christian denominations, and people groups. Based on the 2600-page World Christian Encyclopedia and World Christian Trends. A full-time staff at The Center for the Study of Global Christianity updates and maintains the database. Limited access is free; paid access gets full set of features.
- Jewish Encyclopedia - Contains the complete contents of the 1906 Jewish Encyclopedia. Over 15,000 articles and pictures about the Torah, history, literature, biography, geography, genealogy, and theology. Accessible for free and full-text searchable.
- World Wide Encyclopedia of Christianity - Links to the contents of the Catholic Encyclopedia, Easton's Bible Dictionary, Torrey's Topical Textbook, Elwell's Dictionary of Christian Theology, and other sources.