Exploiting variation from principal and teacher transitions over long administrative data panels in Missouri and Tennessee, we estimate the effects of principal race on the hiring and turnover of racially diverse teachers. Evidence from the two states is strikingly similar. Black principals increase the probability that a newly hired teacher is Black by 5-7 percentage points. This result appears to be partially driven by principals hiring from within their networks of educators with whom they have worked before. Black principals also decrease Black teacher mobility, reducing the probability that a Black teacher changes schools by 2-5 percentage points. Increases in Black teacher hiring and reductions in turnover mean that a change from a White to a Black principal increases the fraction of Black teachers working in a school by about 3 percentage points, on average, increasing exposure of students to Black teachers. Further evidence suggests that assignment to a Black teacher increases the math achievement of Black students, though the presence of a Black principal appears to have positive impacts on Black students' math achievement that is not explained by assignment to Black teachers.