Children must learn individual word meanings and the semantic connections among words. Prior work has probed children’s sensitivity to different semantic relations, but little is known about how this knowledge develops. This study examined whether parents and children jointly created semantic regularities in naturalistic everyday interactions. Forty-four parents and their toddlers (M = 20.4 months, range: 13.2-31 months) participated in a 10-minute free play session with 27 toys from three categories (food, animals, vehicles) while wearing head-mounted eye-trackers. Children’s looking from one object to another was categorized as a same category (e.g., dog-cat) or different category (e.g., dog-car) transition, revealing temporal sequences of semantically related toy play: Children were more likely to transition between objects from the same category and heard more unique words from the same category during these toy transitions. Together, these findings demonstrate that parents and children create semantic regularities for learning through shared attention and action.