Holy Trinity Parish, Coldwater, was founded in 1868. Three farm families in the area asked permission of the pastor of St. Marys, Philothea, to organize a new parish. With permission granted, the new parish took the name "Holy Trinity" and bought the property where the present Holy Trinity Church in Coldwater now stands. Since the founding of the parish in 1868 it had been under the care of the Society of the Precious Blood, but in 1906 care of the parish passed to the secular clergy of the Archdiocese of Cincinnati.
  A frame church was built by the men of the parish and dedicated on October 8, 1868. The new parish grew rapidly, and less than 20 years later more than 80 families belonged to the parish. The church was too small; an addition was built in 1886. This soon proved also to be too small, so a new church was planned. The old church was moved to the site of the present rectory, and a new brick edifice was designed. The cornerstone was laid on June 5, 1898, and the dedication occurred on October 9, 1899. By 1967, the parish numbered 850 families and 3350 souls. It was decided to enlarge the transepts and add balconies. By doing this the church added 250 additional seats, making the present seating about 900.
  At this time Holy Trinity Parish numbers more than 1700 families. The parish has two pastors and a deacon.