First Unitarian traces its roots to 1835, when William Greenleaf Eliot founded the first Unitarian church west of the Mississippi. Eliot is notable for being the grandfather of poet T.S. Eliot and the founder of Washington University in St. Louis. Ministers and members of First Unitarian also helped establish key civic institutions including the St. Louis Public Schools, the St. Louis Art Museum, the Urban League, and the first childcare center west of the Mississippi. Completed in 1917, the current building was designed by notable St. Louis architect William B. Ittner. Ittner is famous for designing over 430 schools nationwide, several of which are on the National Register of Historic Places. First Unitarian represents a rare ecclesiastical example of his work. In 1931, Irma Rombauer used the church kitchen to perfect recipes for The Joy of Cooking, which became one of the most published cookbooks in the United States.

The congregation shares space with several mission-aligned organizations: a nonprofit that provides services for immigrants, a Hebrew School, a Buddhist group, a homeschool network, a dance group, a choir, a summer literacy program, and a program for adults with developmental disabilities. The congregation also provides a free pantry and participates in an interdenominational community lunch program. 

In early 2026, the church experienced a string of robberies, affecting multiple building systems. Thieves stole the copper from the church’s roof, HVAC, and heat pump. The loss of the roof copper was especially impactful, as it had recently been replaced after being damaged during the May 2025 St. Louis tornado. 

An Intervention Fund grant of $39,867 awarded in 2026 will allow the congregation to replace the copper ridge cap on the roof with an alternative that will be theft-resistant while maintaining the building’s historic appearance. The grant will also help fund the replacement of the copper lines in the HVAC system and heat pump. These repairs will help ensure the congregation can continue to host programming, including its summer literacy program.