For time immemorial, foods have not only been a source of gratification to human body needs and the general well-being but also actively moderate the sense of mood (emotional) arousal. In contemporary times, whether due to changing lifestyle or participation of women in the workforce or paucity of time or impatience, fast food restaurants and fast-food dining has become a vogue. These have put huge onuses on the fast-food restaurants or quick service restaurants (QSR) to provide happiness to their consumers and not merely do lip service through the glitzy catchlines. This chapter aims to explore the determinants impacting customer happiness. Data were gathered via an online survey, which was completed by individuals who patronized fast-food establishments such as KFC, McDonald’s, and similar fast-food joints in India. The study utilized a structural equation model to assess the formulated hypotheses. The present chapter also gives insight into managerial implications to bring forth relationship marketing tools in making fast-food consumers happy.