Background: Identifying as an engineer is essential for belonging and student success, yet the social context and professional norms make it more difficult for some students to establish an identity as an engineer. Purpose/Hypothesis: This study investigated whether first-generation college students' funds of knowledge supported their engineering role identity. Design/Methods: Data came from a survey administered across the United States western, southern, and mountain regions in the fall semester of 2018. Only the sample of students who indicated they were the first in their families to attend college was used in the analysis (n = 378). Structural equation modeling was used to understand how first-generation college students' funds of knowledge supported their engineering role identity; measurement invariance was examined to ensure that the model was valid for women and men alike. Results: First-generation college students' funds of knowledge individually supported the components of the engineering role identity development process. Tinkering knowledge from home and perspective-taking helped inform interest and performance/competence beliefs. First-generation college students' bids for external recognition were supported through their mediational skills, their connecting experiences, and their local network of college friends. The bundle of advice, resources, and emotional support from family members was the only fund of knowledge that directly supported students' perceptions of themselves as engineers. Conclusions: The relationships we established between first-generation college students' funds of knowledge and emerging engineering role identities call for engineering educators to integrate students' funds of knowledge into engineering learning and to broaden disciplinary norms of what counts as engineering-relevant knowledge.