Little is known about attention-deficit/hyperactivity disorder (ADHD) in veterans. Practice standards recommend the use of both symptom and performance validity measures in any assessment, and there are salient external incentives associated with ADHD evaluation (stimulant medication access and academic accommodations). The purpose of this study was to evaluate symptom and performance validity measures in a clinical sample of veterans presenting for specialty ADHD evaluation. Patients without a history of a neurocognitive disorder and for whom data were available on all measures (n = 114) completed a clinical interview structured on DSM–5 ADHD symptoms, the Minnesota Multiphasic Personality Inventory-2-Restructured Form (MMPI-2-RF), and the Test of Memory Malingering Trial 1 (TOMM1) as part of a standardized ADHD diagnostic evaluation. Veterans meeting criteria for ADHD were not more likely to overreport symptoms on the MMPI-2-RF nor to fail TOMM1 (score ≤ 41) compared with those who did not meet criteria. Those who overreported symptoms did not endorse significantly more ADHD symptoms; however, those who failed TOMM1 did report significantly more ADHD symptoms (g = 0.90). In the total sample, 19.3% failed TOMM1, 44.7% overreported on the MMPI-2-RF, and 8.8% produced both an overreported MMPI-2-RF and invalid TOMM1. F-r had the highest correlation to TOMM1 scores (r = −.30). These results underscore the importance of assessing both symptom and performance validity in a clinical ADHD evaluation with veterans. In contrast to certain other conditions (e.g., mild traumatic brain injury), ADHD as a diagnosis is not related to higher rates of invalid report/performance in veterans.