The History of St. Denis Church in Diamond Bar

As is the case with many California communities, the city of Diamond Bar traces its roots back to a Mexican land grant. Since the mid-nineteenth century, the parcel on which it is situated changed hands many times, eventually coming into the possession of a cattle rancher who’s "Brand," symbol of a diamond over a bar, was to provide the inspiration for the unincorporated area's name.

Diamond Bar would not become a city until 1989, but the decades leading up to that development saw a rapid growth in population-including the influx of many Catholics who needed a place to worship God and practice the Faith. Originally, those individuals were serviced by the priests of St. Joseph Church in Pomona. Later, the territory became a mission under the auspices of St. Angela Merici Parish in Brea.

On May 10, 1971, the parish of St. Denis was established. A multi-purpose center had been built, where Mass was celebrated, sacraments administered, CCD classes held, and meetings conducted. Initially, only four masses were scheduled each Sunday, but soon the burgeoning parish enrollment made it necessary to increase the number of weekend Masses to nine. Long-time parishioners fondly remember "the old church," which became a hub of activity, both sacred and social, and was in constant use.

The parish needed a rectory; but eventually a house was purchased, which served as both rectory and parish office for nearly two decades.

In the mid1980s, a building campaign was undertaken and ground broken for a new facility which would artfully incorporate the existing structure into the plan. On December 8, 1989, the feast of the Immaculate Conception, the first Mass was celebrated in the new church. Dedication by Cardinal Roger Mahony took place the following April 1.

Widely considered one of the most magnificent worship spaces in the archdiocese, the building combined traditional features and a unique, semicircular seating arrangement with capacity for 1,000. The renovated facility also included a large, enclosed courtyard with fountain and decorative landscaping, just off the main entry to the church. As the the bells in the tower began to resonate throughout the community, the only Catholic Church in Diamond Bar became a familiar landmark-and a witness to God’s presence and love.