The current study investigated the effects of metacognitive and executive function (EF) training on childhood EF (inhibition, working memory [WM], cognitive flexibility, and proactive/reactive control) and academic skills (reading, reasoning, and math) among children from disadvantaged backgrounds. Children (N = 134, M[subscript age] = 8.70 years) were assigned randomly to the three training groups: (a) metacognitive training of basic EF processes (meta-EF), (b) training of basic EF processes (basic-EF), and (c) active controls (active control). They underwent 16 training sessions over the course of 2 months. No effects of EF and/or metacognitive training were found for academic outcomes. However, both meta-EF and basic-EF groups demonstrated greater gains than the active control group on proactive control engagement and WM, suggesting that EF training promotes a shift to more mature ways of engaging EF. Our findings suggest minimal near- and far-transfer effects of metacognitive training but highlight that proactive engagement of EF can be promoted through EF training in children.