Deepfake technology has profoundly impacted society. While it has positive uses, it has also been exploited for malicious purposes, such as disseminating fake news and defaming individuals. However, relatively few studies have focused specifically on the unique harms associated with deepfake technology. Moreover, perceptions of harm are often influenced by the third-person effect (TPE) in which individuals believe that others are more susceptible to risks than themselves. This study addresses these gaps by investigating TPE on seniors’ perceptions of deepfake harms from a nuanced approach where deepfakes could lead to physical, financial, emotional, societal and relational harms. An online survey with 153 participants aged 55 years and above revealed that seniors perceived that they were most susceptible to societal harm. Further, the TPE was present in that seniors felt that others were much more likely to encounter the five types of harms than themselves.