This case study describes the country-level response to the COVID-19 pandemic in Kenya between February 2020 and May 2021. We organize the presentation of COVID-19 response strategies across the five stages of (a) engagement, (b) assessment, (c) planning, (d) action/implementation, and (e) evaluation. We describe the participatory monitoring and evaluation (M&E) process implemented in collaboration with the WHO Regional Office for Africa Monitoring and Evaluation Team. The M&E system was used to organize and make sense of emerging data regarding specific response activities and changing COVID incidence. We share the results of that collaborative sensemaking, with particular attention to our analysis of the factors that facilitated and those that impeded our pandemic response. We conclude with lessons learned and practical implications from Kenya’s experience to help guide future country-level responses to rapidly changing public health crises.