Reference articles on history, science, culture and more
Surprise meSurprise meSubscribe
Encyclopedia

Side altar

Wikipedia contributorsAdapted for Fathomly · View authors
1 min read
Source updated September 3, 2026
Image credit is listed at the end of this article.

In Christianity, a side-altar or bye-altar is an altar that is subordinate to the central or high altar in a church. The term is generally applied to altars situated in bays of the nave, transepts, etc. Side-altars may be recessed in a side-chapel, or simply built against a main aisle wall.

In the Catholic Church, before the liturgical reforms arising from the Second Vatican Council, separate Masses were celebrated simultaneously by other priests at bye-altars, even as there is an ongoing Mass at the high altar. After the Second Vatican Council, this practice disappeared subsequent to the introduction of concelebration at the high altar.

Certain churches in the Evangelical-Lutheran tradition of Christianity retained bye-altars, though their presence in newer churches are not as common today.

Watch videos about Side altarExplainers and documentaries on YouTube (opens in a new tab)

Sources and credits

This article is adapted from the Wikipedia article “Side altar”, written by its contributors and licensed under CC BY-SA 4.0. Fathomly has changed the layout, removed citation markers, navigation and maintenance notices, and adjusted punctuation. This adapted version is shared under the same license. For references, see the original article.

Images, from Wikimedia Commons:

Fathomly is not affiliated with or endorsed by the Wikimedia Foundation. Spotted a problem? Tell us.

Continue exploring

Related topics

Lady chapel

A Lady chapel or lady chapel is a chapel dedicated to Mary, mother of Jesus, particularly one inside a cathedral or other large church. The chapels are also known as a Mary chapel or a Marian chapel, and they are traditionally the largest side chapel of a cathedral, placed eastward from the high altar and forming a projection from the main building, as in Winchester Cathedral.

Public domain

The public domain consists of all creative work to which no exclusive intellectual property rights apply. Those rights may have expired, be forfeit, waived or may be inapplicable.

Catholic Encyclopedia

The Catholic Encyclopedia: An International Work of Reference on the Constitution, Doctrine, Discipline, and History of the Catholic Church, also referred to as the Old Catholic Encyclopedia and the Original Catholic Encyclopedia, is an English-language encyclopedia about Roman Catholicism, published in the United States. It was designed "to give its readers full and authoritative information on the entire cycle of Catholic interests, action and doctrine".