Weight bias is present in children as young as 3 years old; however, research regarding gender differences is mixed. This study examined gender and age differences in weight bias attitudes in a sample of 3‐ to 5‐year‐old pre‐schoolers. Children assigned positive or negative adjectives to thin, average, or large targets and selected one of these targets as their best friend. Girls showed a larger weight bias than boys in both tasks, and weight bias increased with age in the adjective attribution task. Findings clarify previously mixed gender results and demonstrate that while weight bias beliefs strengthen during the pre‐school years, weight bias behavioural intentions do not. The results highlight the importance of continued efforts to address weight bias in young children.