Individuals with intellectual disabilities have a shorter lifespan and significantly higher prevalence of conditions such as hypertension and cardiovascular diseases than healthy individuals. Thus, assessing the elements that contribute to their physical fitness is crucial. This cross-sectional study examined the relationship between the blood pressure and physical fitness of people with intellectual disabilities in South Korea, considering differences across sexes, age groups, physical attributes, and disability levels. It used data from 8502 individuals with intellectual disabilities aged 20-59 years who participated in a survey of a National Fitness Standard Center (NFSC) between 2018 and 2021. A series of t-tests, one-way analysis of variance, logistic regression, and the four-quartile method were used for data analyses. The results showed differences in physical fitness levels between men and women considering all aspects except for BMI (Body Mass Index), with men showing higher blood pressure levels. Lower grip strength, lower PEI (physical efficiency index) scores, and higher BMI were associated with increased blood pressure. Additionally, individuals with higher levels of disability tended to have lower levels of physical fitness, while higher physical fitness levels were associated with lower blood pressure. Therefore, low fitness levels and hypertension risk may be important health indicators for people with intellectual disabilities.