Objective Social isolation and loneliness have been linked to numerous determinants of health and well-being. However, the effects of social isolation and loneliness on oral health remain unclear. The purpose of this study was to examine the effects of social isolation and loneliness on the number of remaining teeth and the rate of tooth loss over time among Chinese older adults. Methods We used three waves of data (2011/2012, 2014 and 2018) from the Chinese Longitudinal Healthy Longevity Survey with 4268 older adults aged 65 and older who were interviewed in at least two waves. The number of remaining teeth was first evaluated at baseline and then subsequently at follow-up visits. Mixed-effects Poisson regression was used to examine the associations between social isolation, loneliness, and both the number of remaining teeth and the rate of tooth loss. Results Social isolation was associated with fewer remaining teeth (beta = -.06, 95% CI = -0.13 to 0.00, p < .05) and accelerated tooth loss (beta = -.02, 95% CI = -0.02 to -0.01, p < .01) after adjusting for sociodemographic covariates, lifestyle and oral hygiene behaviours, physical and cognitive health, and loneliness. Loneliness was neither associated with the number of remaining teeth (beta = .15, 95% CI = -0.01 to 0.30, p = .06) nor with the rate of tooth loss (beta = -.01, 95% CI = -0.02 to 0.00, p = .16) after adjusting for all other factors. Conclusions This study provides strong evidence that social isolation was associated with fewer remaining teeth and accelerated tooth loss among Chinese older adults. These findings expand our knowledge about the impact of social disconnection on tooth loss. More future studies are needed to further examine the associations between social connections and oral conditions using longitudinal cohort studies and intervention studies.