The patron saint of Stella is Saint John the Baptist, celebrated on 24 June. The church named after him stands in the hamlet of San Giovanni, which bears the saint's own name and was the birthplace of Sandro Pertini, seventh President of the Italian Republic: on 24 February 2024 the status of Presidential City was officially granted to Stella precisely for this link, and the president's remains rest in the hamlet's cemetery.
The town's first and only parish until 1567, however, was the church of San Martino di Tours, tradition holding it was built as early as the 5th century; not far away stands the castle of Stella, rebuilt in the first half of the 12th century, which in 1244 hosted Pope Innocent IV for two weeks after he fell ill while travelling to the Council of Lyon.
