Experts often appear to perceive time differently from novices. The current study thus examined perceptions of time as a function of domain expertise. Specifically, individuals with high or low levels of knowledge of American football made judgements of duration for briefly presented words that were unrelated to football (e.g., <i>rooster</i>), football specific (e.g., <i>touchdown</i>), or ambiguous (e.g., <i>huddle</i>). Results showed that high-knowledge individuals judged football-specific words as having been presented for a longer duration than unrelated or ambiguous words. In contrast, low-knowledge participants exhibited no systematic differences in judgements of duration based on the type of word presented. These findings are discussed within a fluency attribution framework, which suggests that experts' fluent perception of domain-relevant stimuli leads to the subjective impression that time slows down in one's domain of expertise.