- a more easterly, inland language attested at a relatively late date in the extensive corpus of Celtiberian. This variety, which Cólera proposed to name northeastern Hispano-Celtic, has long been synonymous with the term Hispano-Celtic and is universally accepted as a Celtic language.
- a more westerly variety of the Atlantic zone (to the west of an imaginary line running north-south and linking Oviedo and Mérida), where there is a corpus of Latin inscriptions containing some linguistic features that are clearly Celtic (Gallaecian). To this more meagrely attested variety, which Cólera  proposed to name northwestern Hispano-Celtic, could possibly be added earlier inscriptions on stelae from the southwest of the Peninsula which some researchers believe represent a Celtic language (Tartessian). This widespread material is likely to represent more than one dialect, for example, numerous examples of genitives plural in -um and -on, as well as -un, and there is at least one inscription with the datives plural in -bor. Western Hispano-Celtic is a term now used to group this western Atlantic-side spectrum of dialects.
The Western Celtic varieties of the Iberian Peninsula share with Celtiberian a sufficient core of distinctive and probably innovative features to justify Hispano-Celtic as a term for a linguistic sub-family as opposed to a purely geographical classification. In Naturalis Historia 3.13 Pliny states that the Celtici of Baetica (now western Andalusia) proceed of the Celtiberians of Lusitania, since they shared common religions, languages, and names for their fortified settlements: Celticos a Celtiberis ex Lusitania advenisse manifestum est sacris, lingua, oppidorum vocabulis, quae cognominibus in Baetica distinguntur. However, the Celtic of the western coastal Iberia, especially in those areas under Phoenician influence, appear to have participated at an early date in linguistic innovations taking part in various parts of the wider Celtic-speaking world as a result of the rapid economic and social development of the 10th-6th centuries BC. Such a situation favored the mixing of dialects and acceptance of some innovative features within the resulting lingua-franca.
As part of the effort to establish an Hispano-Celtic dialect continuum, Lujan (2007) attempted to differentiate the Vettonian Hispano-Celtic dialect from the neighboring Lusitanian language using the personal names of the Vettones to describe the following sound changes (PIE to Proto-Celtic):
- *ō > ā occurs in Enimarus.
- *ō > ū in final syllables is indicated by the suffix of, e. g., Abrunus, Caurunius.
- *ē > ī is attested in the genitive singular Riuei.
- *n̥ > an appears in Argantonius.
- *m̥ > am in names with Amb-.
- *gʷ > b is attested in names such as Bouius, derived from *gʷow- 'cow'.
- *kʷ in PIE *perkʷ-u- 'oak' appears in a lenited form in the name Erguena.
- *p > ɸ > 0 is attested in:
- *perkʷ-u- > ergʷ- in Erguena (see above).
- *plab- > lab- in Laboina.
- *uper- > ur- in Uralus and Urocius.
- However, *p is preserved in Cupiena, a Vettonian name not attested in Lusitania; also in names like Pinara, while *-pl- probably developed into -bl- in names like Ableca.
- Celtiberian language
- Gallaecian language
- Continental Celtic languages
- List of Galician words of Celtic origin
- List of Spanish words of Celtic origin
- Tartessian language
- Celtic languages
- Paleohispanic languages
- Meid, W. Celtiberian Inscriptions (1994). Budapest: Archaeolingua Alapítvány.
- Koch, John T (2010). Celtic from the West Chapter 9: Paradigm Shift? Interpreting Tartessian as Celtic. Oxbow Books, Oxford, UK. pp. 292–293. ISBN 978-1-84217-410-4.
- Cólera, Carlos Jordán (March 16, 2007). "The Celts in the Iberian Peninsula:Celtiberian". e-Keltoi 6: 749–750. Retrieved 16 June 2010.
- Koch, John T. (2006). Celtic Culture: A Historical Encyclopedia. ABC-CLIO. p. 481.
- Koch, John (2009). Tartessian: Celtic from the Southwest at the Dawn of History in Acta Palaeohispanica X Palaeohispanica 9 (2009). Palaeohispanica. pp. 339–351. ISSN 1578-5386. Retrieved 2010-05-17.
- "O'Donnell Lecture 2008 Appendix".
- Wodtko, Dagmar S (2010). Celtic from the West Chapter 11: The Problem of Lusitanian. Oxbow Books, Oxford, UK. pp. 360–361. ISBN 978-1-84217-410-4.
- Koch, John T (2010). Celtic from the West Chapter 9: Paradigm Shift? Interpreting Tartessian as Celtic. Oxbow Books, Oxford, UK. p. 292. ISBN 978-1-84217-410-4.
- Lujan, E.; eds. P.-Y. Lambert & G.-J. Pinault, Geneve, Librairie Droz. (2007). "L'onomastique des Vettons: analyse linguistique". Gaulois et celtique continental: 245–275.
- Wodtko, Dagmar S (2010). Celtic from the West Chapter 11: The Problem of Lusitanian. Oxbow Books, Oxford, UK. p. 351. ISBN 978-1-84217-410-4.