Cantalupo nel Sannio is a town and comune in the province of Isernia, in the Molise region of southern Italy.

The town was known simply as Cantalupo until February 4, 1864, when the denomination nel Sannio was added in order to differentiate it from other villages with the same name.

[3] The specification of nel Sannio is derived from the fact that the village is located in the ancient territory of Samnium, which was inhabited by the Italic tribes known as the Samnites.

[3] The latter explanation is favoured due to the well-established Bulgar presence in the territory of Samnium going back at least to the 7th century.

A substantial population of Cantalupesi settled in Montreal, Quebec, Canada and Anaconda, Montana, United States, where they founded and still maintain the Associazione di Sant'Anna di Cantalupo, named in honour of the village's patron saint, Saint Anne, Christ's maternal grandmother.