This study examined the role of select intrapersonal and microsystem factors in high school adolescents' academic achievement. A combination of factors, derived from an ecological framework, were hypothesized to be unique in their ability to explain greater proportions of variance in academic achievement in adolescents. Participants included 379 high school students (176 males, 193 females) from a mid-western high school in a large metropolitan area with a 53% poverty rate that enrolls approximately 1,500 students. A variety of variables emerged as significant predictors of academic achievement, with social emotional learning, self-efficacy, socio-economic status, parental involvement, peer support, and teacher support all explaining significant proportions of variance in achievement, and some to stronger degrees than others. This lends support to the notion that learning is shaped by a myriad of ecological factors. These findings are discussed with regard to their usefulness in understanding ways in which to target each of the investigated variables to ultimately increase academic achievement in adolescents.