To reduce climate change, governments and global organisations are increasingly recommending the reduced consumption of animal-based foods and a shift to plant-rich diets. However, there is still much confusion amongst the public as to which foods are nutritionally the healthiest and how best to reduce the emission of greenhouse gases. Extensive research has been carried out to assess the motivations for turning to a vegetarian or vegan diet but research into factors influencing the consumption of dairy or plant-based beverages is more limited. This study aimed at determining the current factors that influence the consumption of plant-based milk vs. cow's milk. The participants were 265 adults based in the UK who solely consumed either plant-based milk or cow's milk. Data were gathered through an online cross-sectional survey. Plant-based milk drinkers were likely to have a more left-wing political view than cow's milk drinkers but there was no significant difference between groups in age, gender, physical activity or household income. Results from a binomial logistic regression showed that the influence of environmental and ethical impact, intolerance and allergy concerns and dietary preference enhanced the probability of being a plant-based milk drinker. The influence of health and friends and family reduced the likelihood of being a plant-based milk drinker. These findings may offer valuable insights into the factors influencing milk choices and contribute to the broader dialogue on promoting sustainable nutritional consumption.