There has been an increasing push for school leadership to address inequity in educational outcomes. Yet, most of the relevant studies concerned with direct or mediated effects of leadership. We attempt to address the knowledge gap concerning the moderating effects of school leadership on within- and between-school inequality in student achievement. We use longitudinal data from a survey among 2151 Danish public school teachers coupled with administrative records of student achievement for 5729 students. Using multilevel linear regressions with 8 ^th grade achievement in mathematics and reading as dependent variables, we find a statistically significant negative interaction between teacher-leader dialogue and school SES for mathematics achievement. Our results suggest that teacher-leader dialogue about student outcomes may reduce between-school inequality in achievement.