Sustainable Development Goal 3 (SDG 3 or Global Goal 3), regarding "Good Health and Well-being", is one of the 17 Sustainable Development Goals established by the United Nations in 2015. The official wording is: "To ensure healthy lives and promote well-being for all at all ages." The targets of SDG 3 focus on various aspects of healthy life and healthy lifestyle. Progress towards the targets is measured using 21 indicators. SDG 3 aims to achieve universal health coverage and equitable access of healthcare services to all men and women. It proposes to end the preventable death of newborns, infants and children under five (child mortality) and end epidemics.

SDG 3 has 13 targets and 28 indicators to measure progress toward targets. The first nine targets are outcome targets:

The four means of implementation targets are:

Good health is essential to sustainable development and the 2030 Agenda. It focuses on broader economic and social inequalities, urbanization, climate crisis, and the continuing burden of HIV and other infectious diseases, while not forgetting emerging challenges such as non-communicable diseases.

Progress has been made in increasing life expectancy and reducing some of the common causes of child and maternal mortality. Between 2000 and 2016, the worldwide under-five mortality rate decreased by 47 percent (from 78 deaths per 1,000 live births to 41 deaths per 1,000 live births). Still, the number of children dying under age five is very high: 5.6 million in 2016.

The UNDP reports that "every 2 seconds, someone aged 30 to 70 years dies prematurely from noncommunicable diseasecardiovascular disease, chronic respiratory disease, diabetes or cancer."

According to statistics, globally, "Children face the highest risk of dying in their first month of life at an average global rate of 17 deaths per 1,000 live births in 2023...In comparison, the probability of dying after the first month and before reaching age 1 was estimated at 10 deaths per 1,000 and the probability of dying after reaching age 1 and before reaching age 5 was estimated at 10 deaths per 1,000 in 2023. Globally, 2.3 million children died in the first month of life in 2023 – approximately 6,300 neonatal deaths every day.". Lack of access to quality healthcare is one of the major factors. Neonatal mortality was highest in sub-Saharan Africa and South Asia, with the neonatal mortality rate estimated at 26 and 22 deaths per 1,000 live births, respectively, in 2023.

Significant steps have been made in increasing life expectancy and reducing some of the common causes of child and maternal mortality. "In 2023, the global under-five mortality rate was half of what it was in 2000 – a remarkable achievement that reflects decades of sustained investment and collaboration by governments, donors, health professionals, communities and families. Still, the journey toward ending all preventable child deaths is far from complete. An estimated 4.8 million children died before reaching their fifth birthday in 2023—overwhelmingly preventable deaths. This includes 2.3 million newborns who died within the first 28 days of life and 2.5 million children aged 1–59 months. Beyond early childhood, an additional 2.1 million children, adolescents and youth aged 5–24 also lost their lives".