Fish contain many important nutrients and are primarily known for high n-3 polyunsaturated fatty acids (n-3 PUFA) content. Studies have shown that supplementation of fish oil-derived n-3 PUFA improves muscle mass and strength. Here, we hypothesized that fish consumption might improve muscle strength. To test this hypothesis, we performed this cross-sectional study (n = 29,084) in Tianjin, China. The frequency of fish consumption was assessed using a valid self-administered food frequency questionnaire. Handgrip strength (HGS) was used as the indicator of muscle strength, and was measured using a handheld digital dynamometer. Analysis of covariance was used to examine the relationship between fish consumption and HGS. In men, after adjusted potential confounding factors, the least square means (95% confidence intervals) of HGS across saltwater fish consumption categories were 41.5 (41.1, 43.7) kg for <1 time/week, 44.6 (43.2, 45.8) kg for 1 time/week, and 44.7 (43.3, 46.1) kg for ≥2 to 3 times/week (P for trend <0.001). In men, the least square means (95% confidence intervals) of HGS across the ascending quartiles of dietary n-3 PUFA intake were 43.6 (43.2, 44.4) kg, 43.7 (43.2, 44.6) kg, 44.4 (43.0, 45.8) kg, and 44.6 (43.1, 46.0) kg (P for trend <0.01). The results showed that saltwater fish consumption was positively related to HGS in men, but not in women, suggesting that saltwater fish contain nutrients that may be used to improve HGS.