A significant research gap on socioeconomic determinants of oral health among older persons is that socioeconomic indicators, like employment status, have essentially been problematized and measured using a cross-sectional approach. Based on a life course approach, and using data from a population-representative, face-to-face and longitudinal-retrospective survey focused on older people in Chile (N = 802), we reconstructed representative types of individual employment trajectories and measured their association with different oral health indicators in old age. Our results show that employment trajectories characterized by continuous, formal, full-time employment have a protective effect for multiple oral health indicators among older people. Our study demonstrates the need for public policies on oral health in old age to incorporate a life course approach and to consider the negative impact of constantly working in informal employment or being out of the labor market permanently, particularly in countries like Chile where temporary and informal employment has risen steadily.