Sebastián Ignacio Martínez Muñoz (born 6 June 1993) is a Chilean footballer who plays as a midfielder for Universidad de Concepción.

He debuted on 22 October 2011, in a 1-1 draw of Universidad de Chile against Palestino for the 2011 Torneo Clausura, replacing Gabriel Vargas in the halftime.

[3] In 2024, he signed with Universidad de Concepción from Santiago Wanderers.

[4] He is the younger brother of Christian Martínez, also a product of the Universidad de Chile youth system.

This biographical article related to a Chilean association football midfielder is a stub.