An anonymized dataset used for the manuscript entitled "Acceptability, Appropriateness, and Feasibility of an Integrated Supportive Supervision Checklist for Primary Healthcare Facilities in Tanzania: A Convergent Mixed-Methods Study." The dataset comprises quantitative data collected from healthcare providers and district health managers during the pilot implementation of the Integrated Supportive Supervision (ISS) Checklist in primary healthcare facilities in Tanzania. These data were analyzed using a convergent mixed-methods approach to assess the acceptability, appropriateness, and feasibility of the ISS Checklist.