Baptistery of Novara Cathedral, Early Christian baptistery in Novara, Italy

The baptistery of San Giovanni in Novara is a brick building with an octagonal hall ringed alternately by semicircular apses and rectangular aedicules with barrel vaults, modelled on Roman imperial halls. Eight fluted marble columns with Corinthian capitals, taken from 2nd-century Roman ruins, stand beside each chapel but carry no load, which is borne by the masonry. The 11th-century tiburio and its inner dome raise the structure to the cathedral's scale.

The building was constructed in the early 5th century and stands as the oldest Christian monument in Novara. Marble columns from ancient Roman structures were incorporated into its design.

The interior walls feature frescoes showing scenes from the Book of Revelation. Visitors walking through the space can observe these religious images that decorated the place.

The baptistery stands opposite the cathedral, but it is poorly visible from outside because its entrance is on the far side of the large Antonellian quadriportico. Look for the brick building behind that portico rather than on the square itself. The original octagonal baptismal pool, uncovered in the 1959-1966 restorations, lies below the present floor level.

The octagonal baptismal pool found in the 1959–1966 restorations was originally lined with marble, and the rite was performed by immersion. In medieval times it was replaced by a cylindrical Roman stone urn of the 2nd century, a funerary casket dedicated to Umbrena Polla and signed by the freedwoman Doxa; it now stands in the west niche.