This study aims to examine the capacity of the Theory of Planned Behaviour (TPB) to explain the intention to use social networking sites by older people in two time periods, before and after their confinement by the SARS-CoV-2 virus, as well as the evolution of effects (paths) over time of TPB’s determinants. Based on the samples of 384 and 383 Chilean adults collected before and after confinement, the evolution of the effects (paths) was analysed using the TPB model applying the PLS-SEM technique. In conclusion, as older people begin to use social networking sites to connect with their families and people of interest during confinement, their attitudes become more significant, their perceptions of control become less important, and social pressures remain permanent in time.