The synagogue in Joniškis, 4A Town Avenue, was built in 1823.The synagogue's exterior is a blend of late classicism and romanticism.
The White Synagogue is located south of the Red Synagogue. It was known as a "shul" and was intended for ceremonial occasions. It was used by cantors and chazanim.
The White Synagogue in Joniškis has a rectangular plan, a solid volume, and is covered with a high gabled roof. The façade is divided vertically by pilasters and tall semicircular arched windows, and horizontally by a cornice with small teeth. The roof slopes are covered on all four sides by pediments which, like the walls, are divided symmetrically by pilasters and semicircular arched windows. The exterior of the synagogue is close to secular architecture, with no explicit symbols of Judaism, except for the small semicircular arched windows in the pediments of the rear facades, which are paired with small semicircular arched windows, alluding to the Tables of the Decalogue.
On the eastern side of the building was a spacious men's prayer hall, and on the western side was a vestibule with stairs to the second-floor women's gallery.
After the Second World War, the building was converted into a storage room, and then into a gym. An extension was built in 1964. The layout of the building was changed and the interior destroyed. The synagogue building is currently undergoing restoration.
