Framed by the concept of critical language awareness, this study validated a survey to assess teachers' ideological beliefs and attitudes toward English learners (ELs)/multilingual learners (MLs) in content classrooms. Employing exploratory factor analysis (EFA), the study identified three major constructs of teachers' beliefs and attitudes from a relatively large sample across the U.S. (N = 307). The study further examined whether differences in the constructs can be explained by the teacher's primary role (ESOL vs Content), teaching grade (elementary vs secondary), and subject of teaching (STEM, non-STEM, or both), while controlling for years of teaching as a covariate. Results suggested that ESOL teachers were more inclined toward language-integrated content teaching with a greater level of sensitivity to ELs/MLs than content teachers. For elementary education, content teachers were more inclined toward English-only monolingual pedagogy than ESOL teachers. Teachers of STEM subjects were less inclined toward language-­integrated pedagogy than other teachers. Given the critical role of underlying ideologies in teachers' practices, we argue that a more in-depth self-examination is necessary for teachers to obtain critical awareness of their pedagogical practice. This study adds new insights to the research on critical language awareness by addressing the needs of ELs/MLs in content classrooms.