The author tested a model hypothesizing that students' self-perceived academic support (from parents, teachers, and peers) is related to their achievement directly and indirectly through their own perceived academic engagement. The participants were 270 adolescents (M age = 15.41 years, range = 14–20 years) from 3 grade levels (Forms 3–5, equivalent to Grades 9–11 in the United States) in a Hong Kong secondary school. The school principal and teachers helped to collect data based on these adolescents' responses to a self-report questionnaire, consisting of a demographic profile and 4 scales assessing their self-perceptions of the extent of parental, teacher, and peer support, and their own academic engagement. Academic achievement was measured by self-reported grades in math, English, and Chinese. Structural equation modeling analyses revealed that adolescents' perceived parental, teacher, and peer support were all indirectly related to their academic achievement mediated by their own perceived academic engagement. The strength of the relationships, however, varied by support system, with perceived teacher support to achievement being the strongest, followed closely by perceived parental support, and then perceived peer support. In addition, both perceived parental support and perceived teacher support were directly related to academic achievement. However, perceived teacher support made the most total (direct and indirect) contribution to student achievement. Perceived peer support had the smallest, nonetheless significant, indirect relationship to academic achievement. However, the negative, direct influence of perceived peer support canceled out its positive, indirect influence on academic achievement. [Copyright of Genetic Social and General Psychology Monographs is the property of Routledge . Full article may be available at the publisher's website: http://dx.doi.org/10.3200/MONO.131.2.77-127 ]