Background Health inequalities, including inequalities in oral health, are problems of social injustice worldwide. Evidence on this issue from low-income and middle-income countries is still needed. We aimed to examine the relationship between oral health and different dimensions of socioeconomic position (SEP) in Colombia, a very unequal society emerging from a long-lasting internal armed conflict. Methods Using data from the last Colombian Oral Health Survey (2014), we analysed inequalities in severe untreated caries (≥3 teeth), edentulousness (total tooth loss) and number of missing teeth. Inequalities by education, income, area-level SEP and health insurance scheme were estimated by the relative index of inequality and slope index of inequality (RII and SII, respectively). Results A general pattern of social gradients was observed and significant inequalities for all outcomes and SEP indicators were identified with RII and SII. Relative inequalities were larger for decay by health insurance scheme, with worse decay levels among the uninsured (RII: 2.57; 95% CI 2.11 to 3.13), and in edentulousness (RII: 3.23; 95% CI 1.88 to 5.55) and number of missing teeth (RII: 2.08; 95% CI 1.86 to 2.33) by education, with worse levels of these outcomes among the lower educated groups. Absolute inequalities followed the same pattern. Inequalities were larger in urban areas. Conclusion Health insurance and education appear to be the main contributors to oral health inequalities in Colombia, posing challenges for designing public health strategies and social policies. Tackling health inequalities is crucial for a fairer society in a Colombian post-conflict era and our findings highlight the importance of investing in education policies and universal health care coverage.