Mental imagery is used extensively in the sporting domain. It is used for performance-enhancement purposes, arousal regulation, affective and cognitive modification, and rehabilitation purposes. The purpose of this experiment was to evaluate whether acute exercise and mental imagery of acute exercise have similar effects on cognitive performance, specifically memory function. A within-subject randomized controlled experiment was employed. Participants (N = 24; Mage = 21.5 years) completed two exercise-related visits (i.e., actual exercise and mental imagery of exercise), in a counterbalanced order. The acute-exercise session involved 10 min of intermittent sprints. The mental-imagery session involved a time-matched period of mental imagery. After each manipulation (i.e., acute exercise or mental imagery of acute exercise), memory was evaluated from a paired-associative learning task and a comprehensive evaluation of memory, involving spatial-temporal integration (i.e., what, where, and when aspects of memory). Bayesian analyses were computed to evaluate the effects of actual exercise and mental imagery of exercise on memory function. For the paired-associative learning task, there was moderate evidence in favor of the null hypothesis for a main effect for condition (BF01 = 2.85) and time by condition interaction (BF01 = 3.30). Similarly, there was moderate evidence in favor of the null hypothesis for overall (what-where-when) memory integration (BF01 = 3.37), what-loop (BF01 = 2.34), where-loop (BF01 = 3.45), and when-loop (BF01 = 3.46). This experiment provides moderate evidence in support of the null hypothesis. That is, there was moderate evidence to support a non-differential effect of acute exercise and mental imagery of acute exercise on memory function.