Purpose: People are shaped holistically by dynamic and interrelated individual and social-ecological systems. This perspective has been discussed in the context of varied aspects of bilingual experiences, namely language acquisition and development. Here, we applied a Systems Framework of Bilingualism to language attitudes, which may be especially responsive to social-ecological influences. Methodology: One hundred twenty-three French–English bilingual adults ( Mage = 21.20, SD = 3.21) completed self-report questionnaires on demographic information and their attitudes toward languages. A subset of these bilinguals ( n = 73) completed a social network survey. Data and analysis: We used language-tagged social network analysis and geospatial demographic analysis to examine the role of individual characteristics (i.e., first language), interpersonal language dynamics (i.e., person-to-person interactions), and ecological language dynamics (i.e., neighborhood language exposure). Findings and Conclusions: At an individual level, we found that bilinguals’ language background (i.e., first language) predicted attitudes of solidarity toward a language (i.e., whether a language is associated with personal identity and belongingness). When considering sociolinguistic layers of influence, we found that bilinguals’ social network and neighborhood-level language exposure jointly predicted their attitudes of solidarity toward a language, as well as their attitudes toward the protection of minority languages. Originality: While most studies have examined language experience in a unidimensional nature, the present study investigated multilingual language attitudes by considering multiple systems within a social-ecological framework. Implications: Taken together, the results suggest that several interrelated interpersonal and ecological systems are associated with language attitudes, which could have important implications for planning future language policies in multilingual societies such as Montréal.