Abstract: Loneliness is classically defined as a result of perceiving a discrepancy between the desired quantity and quality of one’s social life and actual social relationships (Perlman and Peplau, 1984). Lifespan research has indicated older adults are among the highest risk for experiencing loneliness because their social network size decreases more frequently than that of younger adults. In part, this is due to the growing risk of losing one’s partner and peers through death, the loss of social roles, and limitations of mobility. Despite this risk, levels of loneliness are highly stable in old age and relatively low compared to other points in the lifespan, likely owing to the improved emotion regulation skills often found among healthy older adults (Mund et al., 2020). However, to the extent that increases in loneliness do occur among older adults, this subset of individuals might be at advanced risk for Alzheimer’s disease (AD) and related neurocognitive disorders (Lara et al., 2019). In the present perspective paper, we use the seed and soil model of neurocognitive disorders to better understand how loneliness impacts the brain to potentially increase one’s risk for AD prior to frank cognitive decline and an AD diagnosis (McDonough and Allen, 2019).