Background <p>Emotion socialization plays a crucial role in children’s emotional development, shaping how they understand, express, and regulate emotions. Little is known about how teachers respond to students’ sadness during middle-childhood, despite teachers’ role in children’s emotional experiences at school.</p> Objective <p>This study examined how elementary school teachers respond to children’s experiences of sadness and whether teachers’ emotion socialization behaviors vary as a function of the type of sad event, children’s coping strategies, and children’s psychopathological symptoms.</p> Methods <p>Fifty female teachers (age: 25–64, <i>M</i> = 46.8, <i>SD</i> = 10.9) completed structured interviews and questionnaires regarding sadness experienced by 346 students. A mixed-method design was employed, combining thematic analysis of interview data with multinomial mixed-effects models to examine associations among events, coping strategies, symptoms, and teacher responses, accounting for clustering within teachers.</p> Results <p>Three categories of emotion socialization behaviors emerged: emotion-focused, problem-focused, and unsupportive responses. Teachers were more likely to use emotion-focused strategies in response to personal events than to school-related events. Higher levels of children’s externalizing symptoms were associated with a greater likelihood of teachers’ emotion-focused responses. An interaction effect indicated that teachers were particularly likely to adopt emotion-focused behaviors when children responded to personal events with non-constructive coping strategies, and variability emerged across teachers.</p> Conclusions <p>Teachers’ responses to children’s sadness are context-sensitive and related to events, children’s behavioral functioning, and individual teacher differences. Results underscore teachers’ role in the socialization of sadness during middle-childhood and highlight the importance of supporting teachers in navigating children’s emotional experiences in school.</p>