Research on parental feeding practices has focused on mothers, often overlooking fathers' perspectives and the influence of child sex. This study examined (1) differences between fathers' and mothers' own eating behaviours, their use of feeding practices, and perceptions of their children's eating behaviours, and (2) the role of child sex in these perceptions and practices. Parents (N = 784; 145 fathers and 639 mothers) of preschoolers (3-5 years, 51.3 % female) from the UK completed an online survey assessing their eating behaviours and feeding practices, and their child's eating behaviours. There were significant sex differences in parents' eating behaviours, with mothers reporting more emotional overeating, hunger, satiety responsiveness, and slowness in eating. Mothers and fathers did not differ in their reports of children's eating behaviours. Girls were reported to have higher levels of satiety responsiveness than boys. When exploring the interaction of parent and child sex in reports of eating behaviour, fathers reported that girls had more desire to drink. Mothers and fathers differed in their reported use of some feeding practices. Both mothers and fathers reported greater use of food for emotion regulation with girls than boys. Fathers used more encouragement of balance and variety with boys. These findings highlight distinct patterns in feeding practices and eating behaviours, influenced by both parent and child sex, suggesting that girls may be at greater risk of receiving feeding practices that contribute to the development of emotional eating. These results emphasize the need to consider the role of sex in future research and the development of tailored feeding guidance.