The patron saint of Sant'Arpino is Saint Elpidius the Bishop, celebrated on 24 May in the Church of Sant'Elpidio Vescovo.
In the past, in tandem with the city on the strait, a feast honouring the Madonna della Lettera was held every 3 June, a celebration now lost with the arrival of new generations. The town holds the archaeological area of ancient Atella and the Teatro Lendi, as well as the Domenico Cirillo public park.