<p>Thailand has entered into a state of super-aging society, leading to a rapid increase in the prevalence of dementia. However, current research on dementia within the community remains scarce. Therefore, the aims of this study were to determine the prevalence of dementia and its associated factors in the community. A cross-sectional study was carried out on individuals registered as older adults at one primary care unit in Khon Kaen between February and May 2024. The participants were chosen using systematic random sampling, and dementia was identified using the Thai version of the Rowland Universal Dementia Assessment Scale (RUDAS), while potential risk factors were collected. The study included a total of 350 older adults. The prevalence of dementia was 31.1%. Among the participants with dementia, significant difficulties were observed in memory recall, visuoconstructional drawing, and judgement. The results of multivariate logistic regression analyses showed that advancing age (adjusted odds ratio [AOR] for age groups 70–79 years and over 80 years were 18.46 and 7.61, respectively), hearing impairment (AOR 5.01), subjective memory complaints (AOR 2.76), past or current alcohol use (AOR 2.83), daytime sleepiness (AOR 3.08), and partial dependence (AOR 15.16) were associated with dementia. Dementia is prevalent among Thai older adults in community setting and has shown an increase of the figure over the last decade. Several modifiable factors, including hearing impairment, subjective memory complaints, alcohol consumption, daytime sleepiness, and functional dependency, have been identified as potential pathways for dementia prevention and early detection facilitation.</p>