Saint Secundus or Secundius (Spanish: San Segundo) is venerated as a Christian missionary and martyr of the 1st century, during the Apostolic Age.

He evangelized the town of Abula, which has been identified as either Abla[1][2] or Ávila, and became its first bishop.

The ancient town of Abula is mentioned by Ptolemy in his Geographia (II 6, 60) as located in the Iberian region of Bastetania.

[3] Secundus is one of the group of Seven Apostolic Men (siete varones apostólicos), Christian clerics ordained in Rome by Saints Peter and Paul and sent to evangelize Spain.

Beside Secundius, this group includes Saints Hesychius, Caecilius, Torquatus, Euphrasius, Indaletius, and Ctesiphon.