Ensuring healthy lives and promoting well-being for all at all ages (SDG 3) is not only a fundamental right and a crucial development goal, but it is also front and centre of the global COVID-19 pandemic. To achieve sustainable development, ensuring health is critical, with the understanding that most of the SDGs either directly relate to health, or health indirectly contributes to their advancement. Given the current situation, reaching universal health coverage continues to be a fundamental objective for all Member States so that no one is indeed left behind on the journey towards achieving Agenda 2030 for sustainable development. We, in UNFPA, UNICEF, UNOSSC and PAHO/WHO, acknowledge the unique value and comparative advantages of South-South and triangular cooperation in implementing the Sustainable Development Goals (SDGs) and in contributing to building forward better. In view of this, documenting and sharing good practices in South-South and triangular cooperation for SDG 3 is of paramount importance. South-South and triangular cooperation strengthens ownership and ingenuity by Southern countries and creates mechanisms for sustainable horizontal partnerships. This publication seeks to highlight success stories and solutions from the global South and how, through South-South and triangular cooperation, these initiatives were shared and scaled-up, or demonstrated readiness for adaptation and replication.