The first Kietaviškės church is mentioned in 1504, while the second was built in 1676. This small wooden church, founded by Leonardas Pociejus, the owner of the Kietaviškės manor, and his wife Regina-Liuda, stood for over two centuries. It was clad in wooden planks and stood on low stone foundations. The church had nine windows, brick floors, and an organ with eight stops. In 1696, services began, and the altars were gilded.
On the initiative of parish priest Kajetonas Čepanas, construction of the current brick Church
of the Holy Trinity began between 1906 and 1915, designed by architects V. Michnevičius and possibly V. Soninas. Built in neo-Baroque style, the church features two towers with Baroque spires and a three-tiered facade. The interior is adorned with Baroque altars and Gothic organs. The churchyard is enclosed by a brick wall with arched gates. Important art monuments have also been preserved, including a portrait of Father K. Čepanas and movable 18th–19th century paintings, The Annunciation of Mary and Mary of the Rosary.