Good sleep quality is important to cognition, physical health, mental well‐being, and creativity—factors critical to academic and professional success. But, undergraduate students often report engaging in short, irregular, and poor‐quality sleep. Anecdotal and questionnaire data suggest that poor sleep habits might be prevalent in students who are in studio‐ or project‐based majors that implicitly encourage consecutive nights of disrupted sleep to complete projects. We investigated sleep quantity and quality using both objective measures (wristband actigraphy monitoring) and subjective measures (sleep diary) in 28 interior design undergraduate students for a 7‐day period. Our primary aim was to measure sleep quantity (total sleep time) and quality (e.g., nighttime awakenings) and to compare whether undergraduate interior design students' objective measures of sleep (actigraphy) differed from their subjective measures (sleep diary). The secondary aim was to investigate detrimental outcomes of poor sleep habits on laboratory‐based measures of cognitive function (symmetry span, prospective memory, Raven's progressive matrices, remote associates task) that were administered pre‐ and poststudy. We found that the interior design students in our study overestimated their total sleep time by 36 minutes, that 79% of students slept for fewer than 7 hours at least three nights per week, and that many students cycled between nights of restricted/short sleep and recovery/long sleep. Importantly, students who maintained short sleep durations, highly variable night‐to‐night sleep durations, or had fragmented sleep (i.e., waking after sleep onset) demonstrated pre‐ to poststudy declines on the laboratory measure of creativity (remote associates task). These findings suggest the need for further investigations, which may lead to a broader discussion of studio culture and the role of the “all‐nighter,” both in professional practice and in design education.