Sergio Melillo (born 16 November 1955) is a Roman Catholic bishop, being the head of the Diocese of Ariano Irpino-Lacedonia since 2015.

After working in public administration during his early 20s, he entered the Pontifical Interregional Seminary in 1983 located in Posillipo (Naples), where he obtained a Licentiate in Dogmatic Theology with emphasis on Ecclesiology.

Melillo also served as the deputy director of the diocesan Caritas and was responsible for the organization of volunteers, civil services, and listening centers from 2000 to 2005.

[2] Melillo was ordained bishop of Ariano Irpino-Lacedonia on 31 July 2015 by the Archbishop of Naples, Cardinal Crescenzio Sepe.

Apostolic nuncio and titular archbishop Adriano Bernardini as well as Giovanni D'Alise, the preceding bishop, served as co-consocrators.