Concerns have been raised regarding middle-aged and older adults’ mental health during the coronavirus outbreak. The aim of the current study was to characterise associations between internet use (frequency and purpose), depression symptoms and Quality of Life (QoL) during the pandemic, in individuals aged 55–75. Data (N = 3491) were drawn from the English longitudinal study of ageing (ELSA) cohort study collected in June/July 2020 (while social distancing measures were in place). Associations with frequency of use were tested using analysis of covariance (ANCOVAS), controlling for covariates such as wealth and education. Type of internet use (for communication, information search) was also analysed amongst frequent users. Significant effects of frequency of use were observed (p = 0.01 for depression, p < 0.001 for QoL), with lower depression symptoms and higher QoL scores amongst more frequent users. Regarding purpose of use, those who reported using the internet for communication purposes had higher QoL. However, use for health-related or Government services information searching was associated with more depression symptoms. Results provide important information regarding the potential benefits of internet use for middle-aged and older people, suggesting that strategies to increase internet usage (particularly for communication) might benefit middle-aged and older adults’ mental health and counter isolation as the coronavirus crisis continues to evolve.