While progress to close racial achievement gaps has stagnated and income achievement gaps have grown, recent case studies enthusiastically describe “transformational” schools, which claim to establish conditions that enable students—primarily poor students of color—to achieve at levels far higher than their social background predicts. Accounts of such schools highlight a widespread belief among their teachers of empowerment over student outcomes despite students’ disadvantages. However, such teacher attitudes have never been analyzed on a broad scale, and many analyses of teacher effects focus solely on teachers’ human capital, overlooking their social-psychological traits. I use novel data on teachers from the nationally representative High School Longitudinal Study of 2009 to test whether teachers’ beliefs that they can overcome students’ social disadvantage are related to higher student achievement, and whether associations are stronger for racial minorities and economically disadvantaged students. Using three-level models, I find a positive association between teachers’ beliefs about social disadvantage and students’ achievement, which appears to stem from both selection and causal mechanisms. Evidence of heterogeneity contradicts academic and popular theory: rather than mattering most for poor students of color, teachers’ beliefs appear especially strongly linked to achievement for the most socioeconomically advantaged African American students.