Alcohol intake is a major modifiable risk factor for many diseases. Alcohol can also damage skeletal muscle health during ageing which in turn increases risk of sarcopenia, frailty and falls but this relationship is understudied. The aim of this study was to model the relationship between a full range of alcohol consumption and components of sarcopenic risk, skeletal muscle mass and function, in middle-aged and younger older-aged men and women. A cross-sectional analyses was undertaken of 196,561 white participants from the UK Biobank with longitudinal analysis also in 12,298 of these participants, with outcome measures for the latter repeated after around four years. For the cross-sectional analysis fractional polynomial curves were fitted in models of measures of skeletal muscle mass, appendicular lean mass/body mass index (ALM/BMI), fat-free mass as a percentage of body weight (FFM%) and grip strength, all predicted from alcohol consumption with models fitted for men and women separately. Alcohol consumption at baseline was based on the mean of up to five dietary recalls, typically over 16 months. Linear regression was used for longitudinal analyses to model the effects of alcohol consumption groups on these measures. All models were adjusted for covariates. In the cross-sectional analysis, modelled values of the muscle mass measures all showed a peak at medium levels of alcohol consumption and a steep decline with increasing alcohol consumption. Modelled differences in muscle mass from zero consumption of alcohol to 160 g/d ranged from 3.6 to 4.9% for ALM/BMI for men and women, respectively, and 3.6 to 6.1% for FFM%. Grip strength consistently increased with alcohol consumption. No association between alcohol consumption and muscle measures were seen in the longitudinal results. Our results suggest that higher levels of alcohol consumption could have detrimental effects on muscle mass in middle- and older-aged men and women.