Objective: Children with ADHD exhibit deficits in academic motivation compared to their peers. Yet conceptualizations of motivation according to prominent motivation theories connected to achievement have not been studied in college-bound youth with ADHD symptoms. Method: This study examined motivation according to these theories, differences in motivation by ADHD symptoms, and how the cross-sectional association between motivation and achievement varies by ADHD symptoms. The sample included 461 first-year college students retrospectively reporting their motivation and achievement in their last year of high school. Results: Results indicated differences in motivation by ADHD symptoms. Mastery achievement goal orientation was uniquely associated with achievement and exerted beneficial effects on achievement at moderate to high ADHD symptom levels. Conclusion: Motivation may operate differently in association with achievement for college-bound youth with ADHD symptoms compared to youth with no to low symptoms.