School climate is widely recognized as an important factor in promoting student academic achievement. The current study investigated the hypothesis that a demanding and supportive school climate, based on authoritative school climate theory, would serve as a protective factor for students living with 1 or no parents at home. Using a statewide sample of 56,508 middle school students from 415 public schools in 1 state, results indicated that student perceptions of disciplinary structure, academic demandingness, and student support all had positive associations with student self-reported grade point average (GPA). In addition, findings showed that academic expectations and student support were more highly associated with GPA for students not living with any parent. Implications for policy and practice are discussed.