Objective.-The aims of this study were to investigate: (1) the prevalence and unadjusted and adjusted odds of 12-month generalized anxiety disorder (GAD) among adults with migraine in comparison to those without migraine; (2) If debilitating pain and/or limitations in instrumental activities of daily living (IADLs) are mediators of the migraine-GAD association; and (3) Factors associated with past year GAD among adults with migraine. Methods.-Secondary data analysis of the nationally representative 2012 Canadian Community Health Survey-Mental Health (CCHS-MS), a population-based survey of community dwellers with a response rate of 68.9%. The first subsample included those with (n=2232) and without migraine (n=19,270), and the second subsample was restricted to those with migraine (n=2232). GAD was based on the WHO-CIDI scale. Results.-Fully, 6% of those with migraines had past year GAD in comparison of 2.1% of those without migraine (P<.001). The socio-demographically adjusted odds of past year GAD were two and a half times higher among those with migraine than those without (OR= 2.46; 95% CI=2.00, 3.02). A path analysis indicated that debilitating pain and limitations in IADLs were mediators in the relationship between migraine and GAD. In the sample restricted to migraineurs, the factors associated with higher odds of 12-month GAD included having a university degree, having low income, being without a confidant, and being male. Conclusions.-Generalized anxiety disorder is robustly associated with migraine and targeted outreach and interventions are warranted.