Objectives: This study examined the psychometric properties of the Turkish versions of the Maladaptive Daydreaming Scale (MDS-16) and its short form (MDS-5), with a particular focus on how the scales function in adults with attention-deficit/hyperactivity disorder (ADHD). Design: Cross-sectional psychometric validation study comparing adults with ADHD to typical controls. Methods: A total of 357 participants (251 with ADHD, 106 controls) completed the MDS-16, MDS-5, and additional measures of ADHD symptoms, excessive mind wandering, dissociation, and anxiety/depression. Results: Confirmatory factor analysis supported the four-factor structure of the MDS-16 and indicated good model fit for the MDS-5. Internal consistency was excellent for the MDS-16 total scale (α =.93) and good for the MDS-5 (α =.87). Multivariate analyses, controlling for sociodemographic variables and comorbid symptom severity, showed significantly higher MD scores in the ADHD group across total and subscale scores (η2 =.17 for Impairment,.14 for Kinesthesia,.08 for Yearning,.04 for Music). Item-level analyses showed that Yearning and Music/Kinesthesia items clustered in the moderate-to-lower AUC range, whereas Impairment items clustered at the highest AUC levels. Convergent validity was supported by moderate correlations between MD scales and ADHD symptoms, excessive mind wandering, and dissociation (r =.51–.63), while ADHD symptoms and excessive mind wandering showed a markedly stronger association (r =.82). Conclusions: The Turkish MDS-16 and MDS-5 demonstrated good validity and reliability, with Yearning and Music/Kinesthesia subscales capturing more MD-specific features, whereas Impairment showed greater overlap with ADHD. Further research is needed to clarify MD–ADHD overlap and improve diagnostic specificity.