BACKGROUND: Movement behaviours are important for infant (0-12 mo) and toddler (1-2 yrs) health and development, yet very little is known about adherence to the 24-hour movement behaviour guidelines and parents perception of these behaviours in these age groups. This study aimed to examine parental perceptions of movement behaviours and adherence to guidelines in a sample of UK parents with children 0-18 months. METHODS: Participants were 216 parent-child dyads from the cross-sectional Movement Behaviour Assessment in Infants and Toddlers (M-BAIT) study. Tummy time, screen time, restraint time and sleep were measured using a parental questionnaire. A sub-sample of parents were asked about their priority areas for their child's health and development. Frequencies were used to describe the proportion of children meeting movement behaviour guidelines, the number of guidelines met and priority areas for parents. Mann-Whitney U-tests (continuous variables) and chi-square tests (categorical variables) were used to assess the differences between boys and girls. RESULTS: For those under 12 months of age, just over 30% of children met tummy time recommendations, 41.3% met the screen time guidelines, 57.8% met restraint guidelines and 76.2% met sleep guidelines. For those 12 months and over, 24.1% met the screen time guidelines, 56.9% met restraint guidelines and 82.8% met sleep guidelines. Parents identified sleep and physical activity as top priorities for their child. Limiting screen time was deemed least important. CONCLUSION: In this sample of UK infants and toddlers (0-18 months), few adhered to the sedentary behaviour and tummy time guidelines, whereas the majority meet sleep guidelines. This mirrors parental priorities; limiting screen time was seen as less important, with sleep and physical activity deemed most important. These findings suggest greater efforts are needed to raise awareness about screen and tummy time, supporting parents and care-providers to promote positive movement behaviours.