This study aimed to evaluate the association of periodontitis with the organoleptic score (OLS)-defined oral malodor after validating OLS with odoriferous sulfur compounds in mouth air among Korean adults. A total of 330 adults aged 47-86 years were recruited from the Yangpyeong health cohort, South Korea, in 2015. Oral malodor was assessed using a 6-point OLS by a trained dentist and validated with the concentrations of hydrogen sulfide (HS) and methyl mercaptan (MM) using a gas chromatographer. Periodontitis was measured by assessing the radiographic alveolar bone loss on digital orthopantomography. Statistical analyses including descriptive statistics, partial correlation, ANOVA, and multivariable logistic regression with putative confounders were applied. OLS was significantly correlated with the concentrations of HS and MM (partial r = 0.401 and 0.392, respectively; both p<0.001) after controlling for confounders. Individuals with periodontitis had 1.8 times the risk of OLS-defined oral malodor in multivariable models (adjusted odds ratio = 1.77 in the model with the number of teeth and 1.82 in the model with denture wearing; p = 0.047 and 0.035, respectively). Periodontitis was associated with OLS-defined oral malodor among Korean adults independent of known confounders. Periodontal conditions should be considered for clinical practice and research of oral malodor.