Designed for middle and high school students to rate the cultural humility levels among their teachers, this two-study article reports on the development and initial validation of the Cultural Humility Scale for Students (CHS-S), which was adapted from the original Cultural Humility Scale used in psychotherapy. Having cultural humility may facilitate positive teacher-student relationships by preventing or responding to cultural differences when they occur. Study 1 validated the scale's use with a sample of middle school students (N = 1522). Exploratory and confirmatory factor analyses supported a two-factor structure (positive factor and negative factor) with 11 total items. Scalar measurement invariance was supported for gender comparisons. Partial scalar models were supported for race/ethnicity and grade comparisons. Compared with boys, girls reported that their teachers displayed significantly higher levels of positive cultural humility (estimate = 0.19, Cohen's d = 0.16, p = .005). Study 2 extended this work to examine high school students (N = 1612) and provided evidence that teacher cultural humility was predictive of teacher-student relationship quality (TSRQ). Results indicated that Black students who rated their teachers as having high cultural humility also reported having significantly more trust in their teachers compared to their White peers (p < .001). In terms of gender, boys who rated their teachers as having lower cultural humility had significantly less trust in their teachers and felt more alienated from their teachers compared to girls (p < .001). Results provide initial evidence that the CHS-S may be a reliable and valid instrument for measuring middle and high school students' perceptions regarding their teachers' cultural humility. Additionally, results suggest that perceived teacher cultural humility is significantly associated with TSRQ (p-values ranged from 0.05 to 0.001 in the areas of Trust, Communication, and Alienation) and could be used to complement evaluations of school climate. Limitations and future directions for research and practice are discussed.