The novel coronavirus (COVID-19) outbreak has affected living standards around the world, and pandemic anxiety has changed social habits. In this context, this paper investigates the relationship between fear of COVID-19 and quality of life, and assesses the mediating effect of loneliness on this relationship among a sample of older adults in Turkey. The study considers data from approximately 400 people, all of whom completed the CASP-19 Quality of Life Scale in Older People, the Loneliness Scale for the Elderly and the Fear of COVID-19 Scale. Confirmatory factor analyses were performed to confirm a one-factor structure for each instrument. Subsequently, mediation analysis, correcting for age as a continuous covariate, was performed to assess the nature of the relationship between fear and quality of life, and the extent to which that relationship is mediated by loneliness. Our study showed that there is a negative and direct relationship between loneliness and quality of life. Another important finding of our research is that fear of COVID-19 has a significant effect on loneliness. Finally, loneliness mediates the relation between fear of COVID-19 and quality of life. This finding strongly suggests that fear of COVID-19 influences quality of life via loneliness. This result is noteworthy, as we could not find any similar finding in the literature.