Most Holy Family Monastery (vaticancatholic.com)

Most Holy Family Monastery (MHFM) is a sedevacantist organisation based in Fillmore, New York, led by the brothers Michael Dimond (born Frederick) and Peter Dimond (born Robert), who use the title "Brother" (Wikipedia; The Buffalo News via BishopAccountability). According to Wikipedia, it was founded in 1967 by Joseph Natale; after Natale's death in 1995 Michael Dimond became head of the community, and it is not approved by the Roman Catholic Diocese of Buffalo, whose spokesperson has said it has no affiliation with the Catholic Church (Wikipedia).

The group rejects the legitimacy of the post–Vatican II popes; see Sedevacantism. In a recorded statement quoted by The Buffalo News in 2010, Robert (Peter) Dimond said the group was best known for "Exposing the Vatican II church and opposing its heretical teachings" (The Buffalo News via BishopAccountability). Its main outlet is the website vaticancatholic.com, which publishes articles, videos and debates; titles include "Antipope Francis: 'Catholics' must not try to convert agnostics" and "The Antichrist Identified!" (vaticancatholic.com; vaticancatholic.com), and its home page has featured a debate on sedevacantism involving Peter Dimond (vaticancatholic.com).

The Southern Poverty Law Center lists the monastery among the "radical traditional Catholic" groups on its hate map for New York (SPLC); Wikipedia dates the designation to February 2017 (Wikipedia). The SPLC has described radical traditionalist Catholics as a major antisemitic movement (SPLC). The SPLC's "radical traditionalist" category is itself contested: a 2023 FBI Richmond memo that drew on it was withdrawn (Detroit Catholic); see Traditionalist Catholic online culture and Judaism and antisemitism.

In 2010 The Buffalo News reported on a lawsuit in which a man who had left the community accused the monastery of taking $1.6 million from him; the Dimonds declined to be interviewed for that story (The Buffalo News via BishopAccountability). In June 2012 a federal district court in New York dismissed the suit's fraud, misrepresentation, racketeering (RICO), deceptive-practices, false-advertising and equitable claims (Religion Clause via ICLRS).