Resumen: This article presents five Latin inscriptions from the Iberian Peninsula in which the existence of a new letter has been detected: an S with a horizontal stroke at the base. They come from the Celtiberian zone: Peralejos de los Escuderos (Soria), Buenafuente del Sistal and Almadrones (Guadalajara), Lara de los Infantes, and Salas de los Infantes (Burgos). They date after the first century BCE. This same sign has recently been discovered in three inscriptions written in both Celtiberian language and Latin alphabet: the Novallas Bronze, and two inscriptions from Peñalba de Villastar (the Great Inscription and a smaller one). The authors therefore propose designating it the Celtiberian S. Idioma: Inglés Año: 2018 Publicado en: Tyche 33 (2018), 183-205 ISSN: 1010-9161 Factor impacto SCIMAGO: 0.119 - Archeology (Q3) - Language and Linguistics (Q3) - History (Q3)