<p>Linguistically, Colombia is divided into two macrodialects: cachaco (interior), which includes the hegemonic dialect group from the capital Bogotá, and costeño (coastal), a stigmatised dialect group. This dichotomy is also prominent in the Colombian social imaginary, and it is reflected in popular folk discourse on language, which in turn manifests itself in Colombian telenovelas, ‘soap operas’. This thesis builds on recent scholarship on the sociolinguistics of fiction (Stamou, 2018a) which centralises fictional discourse as being the principal object of study whilst also attempting to move beyond fidelity checks in television dialect representation, labelled the reflection fallacy (Androutsopoulos, 2010). Nevertheless, authenticity and how it is linguistically indexed are central, and I adopt the position that authenticity matters because my participants believe it does. I therefore explored the language ideologies behind how linguistic variation is indexed in Colombian telenovelas using the semiotic processes of iconisation, fractal recursivity, and erasure (Irvine & Gal, 2000), with the aim of identifying and examining the signature linguistic features (SLF), a sub-set of stereotypical linguistic markers that are higher-order indices of costeño (Johnstone, Andrus, & Danielson, 2006; Silverstein, 2003). Thirty extended interviews were held with actors, producers, directors, script writers, and voice coaches to determine perceptions, with costeño participants feeling their dialect is misrepresented. I also developed a corpus of telenovela data, consisting of 40 episodes taken from ten telenovelas. Whilst wary of “measuring authenticity”, I analyse if the perceived misrepresentation is reflected in telenovelas, as well as investigating how it is constructed, and more importantly, who decides on this depiction of variation. Findings show that the link between perceptions of misrepresentation and actual portrayal is complex and inconsistent; however, storytellers tend to reproduce these SLF, which are “hyperused” to index costeño identity, contributing to perceptions of misrepresentation. Importantly, these storytellers are often cachacos, raising complex questions of authenticity, identity, and representation. Broadly, this thesis contributes to the emerging sociolinguistics of fiction through the present investigation of the understudied Colombian sociolinguistic and telenovela contexts.</p>