The first Kietaviškės church was mentioned in 1504. The second was built in 1676. This church stood for more than two centuries. Its founders were the owner of Kietaviškės manor, Leonardas Pociejus, the voivode of Vitebsk, and his wife Regina-Liuda Pociejienė. Worship services have been held here since 1696. According to the descriptions, it was wooden, clad in boards on the outside, standing on a low stone foundation. There were nine windows made of small panes, the floor made of bricks. There stood an eight-voice organ, and there were three gilded altars.
At the initiative of the pastor Cajetonas Čepanas (1872–1922), the construction of a new, still existing brick St. Trinity Church. St. Trinity Church is a monument of neo-baroque architecture, built in 1906–1915. (architect V. Michnevičius, according to other data - V. Soninas. The church is historic, rectangular in plan, with an apse, 2 towers with baroque helmets, three-tiered. decorated with lots of moldings, statues.The organ stands out with its gothic decor.The churchyard is surrounded by a brick fence with an arched gate.
To this day, 4 local art monuments have survived in the church: Fr. Portrait of K. Čepanas (painter P. Kalpokas, 1922), arnot, movable altar with paintings “Revelation of Mary”, “Marija Rožančinė” (late 18th-early 19th century).