The association of blood pressure (BP) classification defined by the 2017 American College of Cardiology/American Heart Association (ACC/AHA) guideline with cardiometabolic multimorbidity (CMM) remains unclear. The present study aimed to investigate this research gap in the Chinese adults. Cross-sectional data were collected from a population-based cohort conducted in Southern China. Participants were categorized as having normal BP, elevated BP, stage 1 hypertension, and stage 2 hypertension according to the 2017 ACC/AHA guideline. CMM was defined as having two or more of the following diseases: coronary heart disease, stroke, and diabetes. The relationship between the BP classifications and CMM was examined by multivariate logistic regression. A total of 95 649 participants (mean age: 54.3 ± 10.2 years, 60.7% were women) were enrolled in this study. Multivariable-adjusted logistic regression models revealed that stage 1 hypertension (odds ratio [OR], 1.35; 95% confidence interval [CI], 1.03-1.78) and stage 2 hypertension (OR, 3.53; 95% CI, 2.82-4.47) were significantly associated with a higher prevalence of CMM compared with normal BP. The association between stage 1 hypertension and CMM were profound in women (OR, 1.76; 95% CI, 1.17-2.67) and in the middle-aged group (OR, 1.53; 95% CI, 1.02-2.35) compared with men and older individuals, respectively. Our study showed that among Chinese adults, stage 1 hypertension defined by the 2017 ACC/AHA guideline was already associated with higher odds of CMM compared with normal BP, particularly in women and middle-aged participants. Managing stage 1 hypertension may be an important measure to prevent CMM in Chinese adults.© 2023 The Authors. The Journal of Clinical Hypertension published by Wiley Periodicals LLC.