This study investigated the association between fat-to-muscle ratio (FMR) and hypertension. A total of 1592 participants aged ≥ 40 years were included. Participants were divided into four groups by quartiles of FMR. Odds ratio (OR) and 95% confidence interval (CI) was calculated using logistic regression models. Restricted cubic spline was applied to examine the correlation of FMR and hypertension. Of 1592 participants, 943 (59.2%) participants had hypertension. Hypertension risk rose with FMR quartiles. Compared to FMR quartile 1, ORs were 1.496 (95% CI: 1.115-2.006), 2.445 (95% CI: 1.840-3.249), and 5.415 (95% CI: 3.993-7.344) for quartiles 2, 3, and 4, respectively (P for trend <
0.001). Adjusted OR in quartile 4 was 3.015 (95% CI: 2.083-4.365). Restricted cubic spline showed a linear relationship between FMR and hypertension. Adding FMR improved hypertension risk model performance (P = 0.006). Subgroup analysis revealed FMR interactions with sex (P = 0.010) and BMI (P <
0.016), with a higher hypertension risk in females and non-obese individuals. Additionally, versus FMR quartile 1, hypertensive individuals in quartiles 2 (OR: 1.370, 95% CI: 0.900-2.085), 3 (OR: 2.055, 95% CI: 1.374-3.073) and 4 (OR: 3.102, 95% CI: 2.055-4.682) exhibited a significantly elevated risk of atherosclerotic cardiovascular disease (ASCVD). In summary, Elevated FMR independently correlated with hypertension risk, especially in women, or even in non-obese individuals. FMR is a valuable tool for identifying populations with higher hypertension risk and assessing ASCVD risk in hypertensive individuals. Body composition warrants consideration in future hypertension risk studies.