The behavior of zoo animals may be influenced by visitors, with possible implications on animal welfare. We examined the effects of the presence of visitors on the presence and visibility of free-ranging quokkas (Setonix brachyurus) in preferred areas of a walk-through enclosure at Melbourne Zoo, Australia. In a controlled experiment, two visitor treatments were randomly imposed: (1) enclosure open to visitors as normal (“Open”) and (2) enclosure closed to visitors (“Closed”). Treatments were imposed for 2-day periods, with five replicates of each treatment (10 2-day periods in total). Instantaneous point sampling of camera footage at 1-min intervals from 09:00 to 16:00 hr each day recorded the location and visibility of quokkas. Data were analyzed using a two-factor ANOVA (visitor treatment and study area), with 2-day summary values as the unit of analysis. While the presence of quokkas in the study areas was not affected by treatment, fewer (p < 0.05) quokkas were visible from the visitor paths and more (p < 0.05) quokkas were obscured from the visitor paths in the “Open” treatment than the “Closed” treatment. Number of quokkas differed between study areas across treatments (p < 0.01), but there was no interaction (p > 0.05) between visitor treatment and study area. The reduction in quokka visibility when visitors were present indicates that visitors were at least moderately fear provoking for the quokkas in this experiment, but further research is required to examine the effects of visitor presence and behaviors on the behavior and stress physiology of quokkas in walk-through enclosures, as there may be possible welfare implications.