An Aisleless church (German: Saalkirche) is a single-nave church building that consists of a single hall-like room. While similar to the hall church, the aisleless church lacks aisles or passageways either side of the nave separated from the nave by colonnades or arcades, a row of pillars or columns. However, there is often no clear demarcation between the different building forms, and many churches, in the course of their construction history, developed from a combination of different types.
Early aisleless churches were generally small because of the difficulty of spanning a large, open space without using pillars or columns. In many places, where the population made it necessary and money was available, former medieval hall churches were extended over the course of centuries until they became a hall church or basilica. Starting in the Renaissance, the development of new technologies and better building materials allowed larger spaces to be spanned.
The basic form of the church hall is rectangular. Aisleless churches are generally aligned longitudinally so that the altar and choir are located at one of the narrower ends and are facing east. There are rare examples of transept aisleless churches, in which the altar area occupies the short side east of the transept.
This form of church building has proliferated since the Renaissance, especially in Protestant churches. It became the basis of modern church architecture.