The objective of this study was to explore the impact of policy flexibilities deployed during the COVID-19 public health emergency on access, enrollment/retention, benefit utilization, and perceptions of SNAP and WIC. The review identified 37 eligible articles. Twelve studies evaluated policy flexibilities in SNAP only, 21 in WIC only, and 4 in both programs. Across these, 12 studies explored program access, 7 enrollment/retention, 13 benefit utilization, and 15 program perceptions. JBI critical appraisal tools were used to assess risk of bias. The reviewed articles show that although SNAP and WIC participants identified challenges to access, there were increases in enrollment/retention due to policy flexibilities enabling remote services and reducing administrative burden in both programs. Benefit increases led to greater purchase of preferred foods in SNAP and greater access to fruit and vegetables in WIC. Overall, participants were satisfied with the flexibilities and reported most were beneficial for their households. Some implementation challenges were identified by participants and staff. A few studies showed potential risks of bias, including selection bias and confounding bias. COVID-19-related policy flexibilities in SNAP and WIC demonstrated significant improvements in selected program outcomes; however, challenges communicating policy flexibilities to authorized vendors and participants created difficulties to benefiting from the flexibilities. Findings from the evaluations of these flexibilities can inform future program enhancements and long-term regulatory changes.