This foundational guide provides standardized, cross-sectoral messages to support the prevention, detection, and control of zoonotic diseases in Sierra Leone. Developed through the National One Health Platform, it focuses on 12 priority zoonotic diseases including Lassa fever, rabies, anthrax, and Marburg. The guide enables consistent communication across sectors, strengthens community engagement, and supports health system preparedness and emergency response. The Ministry of Health and Sanitation’s Health Education Division and Breakthrough ACTION co-led the guide’s development. Breakthrough ACTION played a pivotal role in coordinating partners, conducting message harmonization workshops, and aligning communication content with global standards and local realities. The guide integrates risk communication principles and provides practical, culturally appropriate messages for use by health workers, animal health officers, religious and traditional leaders, and the media.