Background/Context: Performance character consists of the qualities that allow individuals to regulate their thoughts and actions in ways that support achievement in a particular endeavor. Moral character consists of the qualities relevant to striving for ethical behavior in one's relationships with other individuals and communities. A sizable body of research has demonstrated correlations between student achievement and performance character strengths such as self-discipline, while the relationship between achievement, conduct, and moral character strengths such as integrity is more ambiguous. For both types of character, however, the majority of the extant research literature has focused on relatively small samples of elementary school children, university students, and high-achieving students. Setting: This study took place at three "No Excuses" charter middle schools in a large northeastern city. Charter schools are publicly funded schools that are supervised by state boards of education rather than a local superintendent or school committee. "No Excuses" is a term used to describe high-poverty public schools featuring a strict disciplinary environment, extended school day and year, college preparatory mission, and an intensive focus on traditional reading and mathematics skills. Participants: This study considered the relationship between achievement, conduct, and several character strengths among 488 early adolescents attending three urban charter schools in a large northeastern city. More than 90% of these students identified as African American, Latino, or multi-racial, and two thirds qualified for free or reduced price lunch (a proxy for low socioeconomic status). Research Design: This study combines self-reported survey data on participating students' character strengths with student-level data on grade point average and demerits collected from participants' schools. We fit quantile regression models to consider the relationships between participating students' character strengths, academic achievement, and conduct while controlling for select demographic characteristics. Results: Analyses revealed that students' perseverance, school connectedness and grade level were positive predictors of academic achievement while integrity and demerits were negative predictors of academic achievement. Student conduct was significantly predicted by grade level, grade point average, gender, race/ethnicity and commitment to integrity. In short, both performance and moral character strengths were unique predictors of key student outcomes. Conclusions/Recommendations: In recent years, a number of high-profile charter management organizations have identified cultivating students' performance character as a key lever in promoting student success. Our findings suggest that these organizations would do well to expand their character education programming to include students' moral character strengths as well.