The Thermae Novatianae, also known as the Baths of Timothy (Thermae Novatianae Sive Timotheanae), were built during the reign of Antoninus Pius (138-161). The history of the site is convoluted and contested, but some facts are apparent. The remains are still visible about 20 feet below street level of the via Balbo. The baths stood on the north side of the Vicus Patricius on the ruins of a house set into the slope of the Viminal hill. The basilica was about 30 feet wide and 90 feet long. It was paved with mosaics depicting marine animals. A shallow pool with apsidal protrusions was flanked by a tank at each end, and the terrace was designed from the outset to support the tanks. During the 4th century AD, the hall of the bath complex was converted into the church of Santa Pudenziana, and its structural core was retained with little change.

The Pudens legend is one version of the conversion of the baths into a Christian church. A certain Roman senator named Rufus Pudens was married to a woman named Claudia Britannica, purportedly the daughter of the British king Caractacus, and they lived in a house on the vicus Patricius. After his wife died, Pudens consecrated the house as a place of worship, a domus ecclesia, or house church. (His mother was reportedly a Christian named Priscilla, who had been hospitable to various of the apostles.) He spent his remaining days there with his children: two daughters named Praxedis and Pudentiana and two sons named Novatus and Timotheus. After his death, a baptistry was built on the property, and eventually the abandoned bath complex was converted into a church. Later his estate was deeded to the Christian church at Rome, and it is recorded that these were the only properties that the church at Rome owned up to the time of the Emperor Constantine.

The baths of Timothy are mentioned in several writings. The Christian apologist Saint Justin Martyr was born in Flavia Neopolis in Palestine, but he went to Rome twice and lived "near the baths of Timothy with a man named Martin." He was beheaded in Rome about 165. The apostle Paul made reference to a man named Pudens in one of his epistles (2 Timothy 4:21).

Here are a few resources for additional information about the baths in ancient Rome.