Happiness is a mental or emotional state of well-being defined by positive orpleasant emotions ranging from contentment to intense joy.A variety ofbiological, psychological, religious and philosophical approaches have striven to define happiness and identify its sources. Various research groups, including positive psychology, are employing the scientific method to research questions about what "happiness" is, and how it might be attained.

The United Nations declared 20 March the International Day of Happiness to recognise the relevance of happiness and well-being as universal goals.