Story world absorption is a mental state in which a reader’s attention is captured by immersion in a story. Although there is extensive research on story world absorption in adults, there is very little research on story world absorption in children. This mixed-methods study investigated the mental state of story world absorption in 66 children ages 9–11 years old, asking how they experience that state. Motivated by the hypothesis that, despite differences in their reading frequency, most children can become absorbed by stories, we asked a diverse sample of readers to report on their reading experience. Although 9-year-old frequent readers reported greater overall absorption than 9-year-old occasional readers, 10- and 11-year-old readers reported similar levels of absorption, regardless of their reading frequency. Additionally, frequent and occasional readers across age groups were similar in the extent to which they differentially endorsed the four dimensions of the absorption experience: attention, transportation, emotional engagement, and mental imagery. Semistructured interviews conducted with a subset of the sample (18 children) provided additional information regarding the text types and features that are most likely to absorb child readers. Overall, the findings underline the possibility that both frequent and occasional child readers can become absorbed in a fictional world.