This Post-Summit Impact Report documents the tangible outcomes, partnerships, and actions arising from the 11th African Think Tanks Summit (ATTS 2025), held in Addis Ababa, Ethiopia, from 8-10 October 2025. Convened by the African Capacity Building Foundation (ACBF) in partnership with the African Union Commission (AUC) and the African Union Development Agency (AUDA-NEPAD), the summit brought together over 500 participants from 40+ countries under the theme "From Taxation to Action: Bridging Policy and Implementation in Public Financial Management (PFM) in Africa." Based on a structured survey of 38 respondents from 18 countries and 35+ institutions, the report reveals that 72% of participants took concrete actions influenced by the summit, with 92% reporting new partnerships or collaborations established or under discussion. The survey captures actions including advocacy initiatives, training programs, policy reform efforts, research projects, and cross-country collaborations. Notable outcomes include joint research initiatives, grant proposals, Memoranda of Understanding, and the launch of innovative ventures including an AI company recruiting talent across Africa. The report also synthesizes qualitative feedback from participants, highlighting the summit's role as a catalyst for networking, inspiration, and practical action. Strategic findings and recommendations for ATTS 2026 are presented, emphasizing the need for sustained follow-up mechanisms, youth engagement, and structured research-to-policy pathways.