Catholicism Wiki is an online encyclopedia focused on Catholic faith, history, worship, and church life. Its main page welcomes readers to a collection of more than 119,000 articles, offering reference material for people exploring Catholic teaching and related subjects. The site organizes its content into areas including belief and doctrine, Scripture and Tradition, sacraments and worship, saints and people, history and councils, and devotion and Church life.

Readers can also browse articles about the life of Christ, Gospel events, miracles, parables, and the Sermon on the Mount. Featured content highlights topics such as the Book of Genesis, while daily sections provide information about saints commemorated and the liturgical calendar. Visitors can search, browse, view recent changes, and contribute to the project, with account creation and article-editing tools available.

The site also invites donations to support its work. Catholicism Wiki states that its content is available under the Creative Commons Attribution-ShareAlike 4. 0 International license unless otherwise noted, making it a collaborative resource for learning about Catholicism