This study examined how self-beliefs, particularly reading mindset and self-efficacy, interact together to predict reading-specific achievement goals and engagement as well as reading achievement in fourth-grade students. Latent profile analysis identified three profiles (n = 206): Confident and Fixed Mindset, Moderately Confident and Neutral Mindset, and Confident and Growth Mindset. Compared to the Confident Growth Mindset profile, the Confident Fixed Mindset profile had higher performance goals and lower behavioural engagement and reading achievement. The Confident Fixed Mindset profile showed even lower reading achievement than the Moderately Confident and Neutral Mindset profile on school English/Language Arts grade and vocabulary performance. Lastly, the Confident Growth Mindset profile showed higher levels of behavioural and cognitive engagement than the Moderately Confident and Neutral Mindset profile. Overall, the effects of mindset supersede self-efficacy on reading-related outcomes, suggesting the importance of providing support that promotes a growth mindset before upper elementary students endorse a fixed mindset.