Objective: To explore the association between cardiometabolic multimorbidity and frailty among middle-aged and older adults in China. Methods: Data were derived from the 2013 wave of the China Longitudinal Healthy Longevity Survey, including a total of 6,179 individuals aged 45 years and above with complete follow-up records. Basic demographic information was collected, and frailty status was assessed using a physical frailty scale. Generalized linear models were employed to analyze the association between the number and combinations of cardiometabolic conditions—such as hypertension, diabetes, heart disease, and stroke—and frailty. Results: The prevalence of cardiometabolic multimorbidity among middle-aged and older adults was 14.23%. After adjusting for sociodemographic covariates, individuals with cardiometabolic multimorbidity had a significantly increased risk of frailty compared to those without such conditions (OR = 1.78, 95% CI: 1.45–2.19), along with higher frailty scale scores (β = 0.26, 95% CI: 0.19–0.34). Compared to individuals without cardiometabolic diseases, those with both hypertension and stroke (OR = 1.18, 95% CI: 1.06–1.31) and those with hypertension, heart disease, and stroke (OR = 1.46, 95% CI: 1.24–1.73) exhibited notably higher frailty risks. Conclusion: There is a significant association between cardiometabolic multimorbidity and frailty in middle-aged and older adults in China, particularly for comorbidity patterns involving hypertension. These findings provide evidence for developing targeted health interventions for aging populations.