A p-type modified quadratic gain buck-boost (PMQBB) converter is proposed in this paper. PMQBB converter topology evolution is based on the integration of a modified quadratic boost configuration with the p-type converter structure. Both of the inductors are in continuous conduction mode (CCM). The proposed PMQBB converter’s key features include a reduced component count, lower order, high voltage gain, and continuous input current. The proposed PMQBB converter exhibits a buck capability at a duty ratio D ≤ 0.2929. This paper provides a comprehensive description of the PMQBB converter, including its steady-state analysis, operating modes, and analysis of semiconductor voltage and current stress. To emphasize the PMQBB converter, a detailed comparative study is presented. A 40/400 V, 300 W hardware prototype is tested to authenticate the converter’s performance. The experimental outcomes validate the superior performance and efficiency of the PMQBB converter, highlighting its suitability for high-gain applications.