Distinguishing Mainstream LDS from Fundamentalist Mormon Groups

Understand the key differences between The Church of Jesus Christ of Latter-day Saints and various fundamentalist factions.

By Garret Merkley · Explainer · Jun 9, 2026

Branched from Life in Modern Fundamentalist Polygamous Communities

Quick take

The Church of Jesus Christ of Latter-day Saints (mainstream LDS) officially discontinued polygamy in 1890 and excommunicates members who practice it.
Fundamentalist Mormon groups are independent factions that broke off from the mainstream church, primarily to continue the practice of plural marriage.
Mainstream LDS is a global, centralized faith, while fundamentalist groups are typically smaller, insular, and have diverse leadership structures.
Confusing the two can be inaccurate and disrespectful to members of the mainstream church.

The Church of Jesus Christ of Latter-day Saints (often referred to as the LDS Church or mainstream Mormons) is a global faith with over 17 million members worldwide, headquartered in Salt Lake City, Utah. Fundamentalist Mormon groups, on the other hand, are much smaller, independent factions that separated from the mainstream church, primarily because they wished to continue the practice of plural marriage (polygamy) after the LDS Church officially discontinued it. These groups are not affiliated with or recognized by the mainstream Church of Jesus Christ of Latter-day Saints.

Polygamy: The Primary Dividing Line

The most significant and defining difference between mainstream LDS and fundamentalist groups is the practice of polygamy. The Church of Jesus Christ of Latter-day Saints officially ended the practice of plural marriage in 1890 with the issuance of the Manifesto by President Wilford Woodruff, and it strictly forbids and excommunicates any members who practice it today. Fundamentalist groups, however, believe that plural marriage is a necessary doctrine for exaltation and continue to practice it, often in secrecy or isolated communities. Many fundamentalist groups trace their lineage back to individuals who resisted the mainstream church's decision to cease polygamy.

Priesthood Authority and Governance

The mainstream Church of Jesus Christ of Latter-day Saints has a highly centralized and global leadership structure, led by a prophet and twelve apostles. Priesthood authority is conferred through a clear, unbroken line of succession. Fundamentalist groups, by contrast, have diverse and often contested leadership structures. Their leaders typically claim authority through lineal descent from early Mormon polygamists, through new revelations, or by asserting themselves as the rightful inheritors of original priesthood keys. There is no single, unified fundamentalist organization; rather, there are many distinct groups, each with its own leader(s) and interpretations.

Distinct Beliefs and Social Integration

While both mainstream LDS and fundamentalist groups share historical roots and foundational scriptures like the Book of Mormon, their interpretations and additional doctrines can vary significantly. Mainstream LDS culture is generally integrated into broader society, encouraging education, civic participation, and missionary work globally. Fundamentalist groups often maintain more insular communities, sometimes practicing communal living, and may adhere to more conservative social practices, including distinct dress codes or limited interaction with outsiders. Their emphasis on continuing polygamy often leads to legal and social isolation, unlike the mainstream church which actively seeks to be a respected global faith.

Understanding these distinctions is crucial for accurate reporting, respectful dialogue, and avoiding harmful generalizations. Confusing the mainstream Church of Jesus Christ of Latter-day Saints with fundamentalist groups not only misrepresents a global religion but also overlooks the complex historical and theological reasons for their separation. It helps clarify public perception and acknowledges the distinct identities of each group.

Are all Latter-day Saints polygamists?

No. The Church of Jesus Christ of Latter-day Saints officially discontinued the practice of polygamy in 1890, and any members practicing it today are excommunicated. Only fundamentalist groups practice plural marriage.

Are fundamentalist Mormon groups part of the mainstream Church of Jesus Christ of Latter-day Saints?

No, they are entirely separate and independent organizations. The mainstream Church has no affiliation with fundamentalist groups and condemns their practices.

When did the mainstream church officially stop practicing polygamy?

The official end of polygamy for The Church of Jesus Christ of Latter-day Saints came with the 1890 Manifesto issued by President Wilford Woodruff, which was further reinforced by subsequent declarations.

Do fundamentalist groups have a single, common leader?

No. There are many different fundamentalist groups, each with its own leadership, beliefs, and practices. There is no unified fundamentalist organization.

Is it offensive to confuse mainstream Latter-day Saints with fundamentalist groups?

Yes, generally it is. Members of The Church of Jesus Christ of Latter-day Saints often feel misrepresented and insulted when they are confused with groups that practice polygamy, which their church officially forbids.

Sources

The Church of Jesus Christ of Latter-day Saints, "Plural Marriage and Families in Early Utah"
The Church of Jesus Christ of Latter-day Saints, "The Manifesto and the End of Plural Marriage"