Oral health gained attention worldwide as it exerted unfavourable and undesired influences on an individual’s daily lives and wellbeing, especially among the rural population. In order to increase the understanding on the oral health among the rural community, this study aimed to determine the oral health knowledge and practice and its association with sociodemographic characteristics among the longhouse residents in Julau, Sarawak. In this cross-sectional study, a total of 105 residents were recruited from five longhouses, namely Rumah Panjang Mengga, Rumah Panjang Ikeh, Rumah Panjang Michael, Rumah Panjang Budit, and Rumah Panjang Manju. Information related to sociodemographic characteristics, as well as oral health knowledge and practice was gathered through face-to-face interview by using a structured questionnaire. Spearman rho correlation test, Mann-Whitney U-test, and Krukal-Wallis H-test were applied during data analysis. Median (interquartile) age of the children and adults was 10.0 (5.0) and 50.0 (22.0) years old, respectively. Findings revealed that oral health knowledge and practices among participants, both children and adults were inadequate as a high proportion of the participants were unable to provide answers for oral health related questions (functions of fluoride and correlation between gum disease with heart disease) and several oral health practices (regular oral check-up, change of toothbrush, and consumption of sweetened food) were also not being engaged in the daily life among the children and adult participants. A significant correlation was found between age and knowledge score among adult participants (rs = -0.389, p < 0.001). Besides, significant higher oral health knowledge score were found among adult participants with higher education level (H = 27.466; p < 0.001) and significant higher in oral health practice score was found among unemployed adult participants when compared to self-employed and employed workers for government and private (H = 9.631, p = 0.008). In conclusion, younger and educated participants are more knowledgeable regarding oral health. Engagement of oral health practices were related to occupation of the adult participants. Provision of health education and education aid for longhouse community should be continued taking into consideration age, level of education level, and even occupation in order to improve their oral health knowledge and practice.