In this dissertation, I explore the sociolinguistic perception of stylistic variation by native Spanish speakers and second language learners of Spanish. Within the field of Hispanic sociolinguistics and there is growing interest in studying the social information that listeners extract from language variation that speakers employ (e.g., Chappell, 2019; Walker et al., 2014). Meanwhile, in the field of second language acquisition, researchers are exploring the perceptive side of communicative competence and seek to determine the extent to which second language learners are attentive to the social meanings associated with language variation (e.g., Geeslin & Schmidt, 2018; Schmidt, 2018). In an effort to add to this body of scholarship, I used a matched-guise task to investigate the language attitudes that listeners have toward four variable linguistic structures of Spanish: "ser/estar" + ADJ, future-time reference, reduction of "para (pa)," and syllable final /s/-weakening. Additionally, an English language matched-guise task, constructed around the variable ING (e.g., cooking vs. cookin'), was used to establish a baseline of sociolinguistic perception for L1 English participants. In total, 125 participants (17 native Spanish of speakers, 108 learners of Spanish) completed a series of research tasks including an English matched-guise task, Spanish matched-guise task, a dialect identification task, a proficiency measure, and a background questionnaire. The research tasks incorporated audio stimuli that were digitally manipulated using a copy and splice technique (e.g., Walker et al., 2014; Campbell-Kibler, 2007) producing nearly identical recordings that only differ based on the linguistic variants under investigation. The results from the English matched-guise task indicate that the participants for whom English was a first language, rated speaker guises differentially depending on the linguistic variant present ("-in" or -"ing") in terms of perceived formality, professionalism, and education level. The results of the Spanish matched-guise task provide an in-depth look into the ways in which social meaning is indexed by variable linguistic structures of Spanish by way of language attitudes and also demonstrates that learners of a second language can and do form attitudes toward speakers and variable language forms in that second language. The linguistic variables included in this study most consistently influenced participant attitudes with respect to perceived professionalism, formality, intelligence and education level. The language learners with high degrees of proficiency in Spanish and more experience in the Spanish-speaking world often had attitudes that resembled those of their native speaker counterparts. This project expands our understanding of the sociolinguistic perception of, and social meaning associated with, language variation in Spanish. Furthermore, the findings offer a window into how second language learners interact with the social information attached to language variation as part of building sociolinguistic and communicative competence. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]