This study examined the unique and interactive effects of receptive language ability and ADHD behaviors on six school readiness outcomes, over and above the effects of socioeconomic status, in 49 preschoolers (Mage = 3.98, SDage = .58; 53.06% female) recruited from Head Start-affiliated classrooms. Hierarchical regression analyses revealed unique positive associations between receptive language ability and cognitive and mathematics readiness, and unique negative associations between ADHD behaviors and social-emotional, physical, cognitive, and literacy readiness. Moderation analyses indicated that at higher, but not lower, levels of ADHD behaviors, lower receptive language ability was associated with lower social-emotional readiness. Results highlight that, when considered together, children’s receptive language ability and ADHD behaviors vary in how they predict school readiness. Further, results provide preliminary evidence for ADHD behaviors as a risk factor in the association between receptive language deficits and social-emotional school readiness. Educational and clinical practice implications are discussed. (author abstract)