Purpose: The purpose of this mixed methods study was to investigate how teachers in the United States understand and perceive developmental language disorder (DLD). This study used a survey to examine teachers' understanding of DLD and the impact of DLD at school to inform advocacy efforts within the discipline of communication sciences and disorders (CSD) and collaborations between speech-language pathologists (SLPs) and teachers. Method: The survey was administered online via Qualtrics and consisted of 27 closed-response questions (i.e., Likert scale or multiple-choice) and four open-response questions. We analyzed the closed-response questions using descriptive statistics and logistic regression. The open-response questions were analyzed using a summative content analysis. Results: Two hundred four responses were included in the analysis. Survey respondents successfully identified language-based activities that would be difficult for children with DLD, such as participating in conversations. Many respondents were not familiar with the term DLD nor the lifelong nature of the disorder. Respondents' self-rated ability to recognize students with DLD, determine the educational impact of DLD, and use classroom accommodations varied based on type of teaching role, grade taught, and previous training in language disorders. Content analysis of open responses revealed four categories capturing respondents' descriptions of DLD: social impact, communication, school environment, and teacher insight. Many respondents felt uncertain about characteristics of DLD and its impact across the school day. Conclusions: Although many survey respondents were unfamiliar with the term DLD and associated diagnostic criteria, they accurately identified many tasks that would be difficult for students with DLD on both closed-response and open-response questions. Practical implications for SLPs and future directions for CSD researchers are provided to improve DLD awareness efforts and to establish shared terminology about language impairment among CSD researchers, practicing SLPs, and educators.