The COVID-19 pandemic has put more than just our physical health at risk. Due to containment measures, people have become increasingly isolated and have drastically reduced their daily social interactions. Many studies have already shown the negative effects of these measures, including fatalism. However, research linking fatalism during COVID-19 to well-being indicators is still limited. The goal of this study is to examine the relationship between COVID-19-related fatalism and well-being indicators, as well as the role of loneliness in moderating this relationship. Data was collected from 1,036 adults in Peru through an online survey that included the Quality-of-Life Index, the Fatalism Facing COVID-19 Scale, the Loneliness Scale, and the Mood Assessment Scale. Three models were tested using linear regression and ordinary least squares with bias-corrected bootstrapping. The results indicate that fatalism has a negative impact on quality of life and a positive effect on negative affect, and loneliness moderates both relationships, supporting the conclusion that fatalism exacerbates the effect of well-being indicators and negative affect.