Research Background: Quality of sleep refers to how effectively an individual’s sleep restores physical energy, emotional balance, and cognitive functioning. Level of happiness refers to an individual’s overall subjective experience of well-being, positive emotions, and life satisfaction. Sleep quality and happiness are closely interconnected, as the restorative aspects of sleep significantly influence emotional well-being and life satisfaction. That way in this study, investigator, to find out the impact of sleep quality on adults level of happiness. Objectives: The study objective was to find out the effect of sleep quality on happiness among the adults. Another objective was to examine the significant difference in happiness among the adults of excellent, moderate and poor sleep quality. Procedure: The study one hundred twenty adult individuals were selected from different location. The purposive sampling technique was used for the selection of the samples. The selected samples age range were between 30 to 40 years. The study sleep quality was independent variable and happiness was dependent variable. The study Happiness Scale developed by Himanshi Rastogi and Janki Moorjani has been used. Conclusions: It can be concluded that the adults of excellent sleep quality, and moderate sleep quality has found higher level happiness than adults of poor sleep quality as well as there is no significant difference in happiness between adults of excellent and moderate sleep quality.