This systematic literature review (SLR) assessed the humanistic and economic burden of focal epilepsy and primary generalized tonic-clonic seizures (PGTCS) in adults to evaluate these domains in both populations and identify evidence gaps to inform future research. A search was conducted on December 7, 2022, using MEDLINE and Embase to identify studies published from 2012 onwards reporting humanistic burden (patient-reported or caregiver-reported outcomes or utilities, qualitative evaluations), economic burden (productivity loss, caregiver and societal costs of epilepsy), and sleep-related outcomes. Of the 2830 citations identified, 136 were included. Most studies were in the focal epilepsy population; very few studies reported outcomes in the PGTCS population. The presence of epilepsy-specific instruments varied based on the domain evaluated. Epilepsy exerted considerable humanistic and economic burden. Indicators of poor disease control (e.g., high seizure frequency, resistance to anti-seizure medications, polypharmacy) increased epilepsy burden. Seizure frequency and type, disease severity, and polypharmacy also affected work productivity. Adults with epilepsy, particularly focal epilepsy, reported higher indirect costs, more sick days accrued, and early entry into retirement. Caregivers similarly reported high productivity loss and absenteeism related to caregiving duties. The results of this SLR highlight the high humanistic and economic burden of focal epilepsy and PGTCS, although limited data were available for the PGTCS population. The results include patient-reported outcome data specific to focal epilepsy and PGTCS, expanding the limited humanistic burden evidence identified in previous reviews, and show the effect of poor disease control on individuals' lives and as a driver of indirect costs. PLAIN LANGUAGE SUMMARY: Our systematic literature review identified studies that evaluated the impact of focal epilepsy and primary generalized tonic-clonic seizures on patients and their caregivers. We found that focal epilepsy negatively impacted patients' mental health and sleep and was associated with higher indirect costs and lower work productivity in people with more severe disease. The impact of primary generalized tonic-clonic seizures on patients was rarely reported, and future research is needed.