Prior research indicates a strong relationship between reading motivation and reading performance. However, most studies include predominately White samples, and limited research exists for young students of color. This dissertation attempts to address this gap in the research literature, and advance discussions about closing racial/ethnic and gender achievement gaps. Part one analyzes two large datasets to calculate self-reported reading motivation levels by student subgroup, and estimates predictive models to explore reading motivation’s relationship to achievement. Descriptive findings show average reading motivation levels are high among all children including children from in different racial/ethnic and gender subgroups. Predictive results show that the SDQ reading sub-scale (third-grade reading motivation) alone explains between three and five percent of the variance in fifth-grade achievement. However, after controlling for student background characteristics, early reading motivation is not a strong predictor of later achievement, but can still enhance a teacher’s understanding of how a student feels about and their perceived competence in reading. In Part two, I develop, pilot, and validate a reading motivation instrument for kindergarten students. Results indicate that it is a reliable instrument that measures two dimensions of reading motivation. However, the scale is not strongly predictive of concurrent reading achievement.