We compared working memory (WM) for the location of social versus non‐social targets in infant siblings of children with Autism Spectrum Disorders (sibs‐ASD, n = 25) and of typically developing children (sibs‐TD, n = 30) at 6.5 and 9 months of age. There was a significant interaction of risk group and target type on WM, in which the sibs‐ASD had better WM for non‐social targets as compared with controls. There was no group by stimulus interaction on two non‐memory measures. The results suggest that the increased competency of sibs‐ASD in WM (creating, updating and using transient representations) for non‐social stimuli distinguishes them from sibs‐TD by 9 months of age. This early emerging strength is discussed as a developmental pathway that may have implications for social attention and learning in children at risk for ASD.