This study aimed to verify the different effects of peer support on academic hatred depending on the levels of teachers' academic pressure. Additionally, we examined the effects of academic hatred on academic burnout and engagement by applying the job demand-resources (JD-R) model. Data were collected from 43 classes at 8 high schools (N = 1015, 94.2% response rate, 57.3% women) in South Korea. The results of a multigroup analysis were as follows: (1) peer support served as an important resource in classrooms experiencing high teachers' academic pressures; (2) peer support directly affected academic burnout and engagement, and reduced academic hatred; and (3) reduced academic hatred served as a mediator for lower burnout rate and increased engagement.