Aeclanum (also spelled Aeculanum, Eclano, Ἀικούλανον) was an ancient town of Samnium, Southern Italy, about 25 km east-southeast of Beneventum, on the Via Appia. It lies in Passo di Mirabella, near the modern Mirabella Eclano.
It is now an archaeological park.
Aeclanum was on a promontory naturally defended, to some extent, by a steep slope on the south side down to the river Calore, while the north side lay open towards the crest of the ridge that where the Via Appia ran. This led through Lacus Ampsanctus to Aquilonia and Venusia. Two other routes to Apulia, the Via Aemilia in Hirpinis and Via Aurelia Aeclanensis, diverged nearby, leading through Aequum Tuticum to Luceria and through Trivicum to Herdoniae respectively. The road from Aeclanum to Abellinum (modern Atripalda, near Avellino) may also follow an ancient line.
Today there are ruins of the city walls, of an aqueduct, baths and an amphitheatre; nearly 400 inscriptions have also been discovered.