The parish church of Sinio, dedicated to St. Frontiniano martyr, was completely rebuilt between 1821 and 1825 upon the initiative of the Municipality, of the parish priest father Bartolomeo Loggero, and of the Del Carretto marquises (who owned a side altar of St. Carlo), on the basis of a previous project attributed to the count architect, Carlo Emanuele Rangone.
The top of church tower, still based on an existing bell tower, was reshaped in 1828.
Stylistically, the sacred building, built on the site where the previous church of the medieval “villa” was situated, presents neoclassical styles, especially on the brick façade while late-baroque styles are shown in the inside.
The organ on the tribune (or dais) is dated 1870, a work by the Collinos from Turin. Only later were the internal structures completed.
The fresco decorations and figures (works by the painters Davico, Pene, and Peluffo) were only finished in 1888. The Stations of the Cross are dated 1893.
Within, where the side altars dedicated to Our Lady of the Rosary, to St. Carlo Borromeo, and to St. Elizabeth of Hungary are also highlighted, the following can be admired, as well: a large altarpiece on the choir by Agostino Cottolengo in 1845, the nineteenth-century pulpit, several wooden statues of various ages, as well as paintings by Adalberto Minelli (1804) and Rodolfo Morgari (1891) on the sacred tables.
Of particular prestige is the high altar with a baroque marble installation and valued baroque friezes preserved with the balustrade of the presbytery.
The remarkable stucco baptismal font is the work of Oreste Torello from 1920, commissioned by the parish priest father Olindo Marchisio.