Holy Trinity is blessed with a large number of beautiful and meaningful mosaics. They include three very large wall mosaics within the church building (identified as 1, 2 & 3 in green on the opposing page), a set of the fourteen Stations of the Cross (Roman numerals I through XIV in red), mosaic emblems at the south external façade (4 in blue), and a mosaic portrait of Our Lady of Perpetual Help (5 in blue).

Of the three large mosaics, the first is highly visible on the north wall of the nave of the church. The second is in a hallway and is best viewed through windows in the video library (and liturgy for children) room. The third is on the west wall within the Blessed Sacrament chapel.

Although there is little evidence available to determine the originations of most of these mosaics, two are signed. The large wall mosaic featuring Jesus with children was created by P. Rivet, while the large mural of Lourdes in the Blessed Sacrament Chapel was by A.M. Schwalm. They were both purchased from Italy through the Cotter Religious Arts Company. The Stations of the Cross were also created in Italy.