Attention deficit hyperactivity disorder (ADHD) is associated with diverse cognitive deficits of which problems related to memory and learning are well-established but poorly understood. In an online experiment, we studied whether verbal memory impairment in adult ADHD is related to differences in spontaneous use of memory strategies that hinge upon metacognitive and executive skills. Eighty-one ADHD adults and 209 neurotypical controls performed a Word List Learning task where the same words were presented three times, each time coupled with an open strategy report. Bayesian analyses indicated that the ADHD group recalled less words, did not differ from controls in efficacy of strategy use, but exhibited more limited strategy use than the controls. This suggests that less versatile strategy employment, possibly related to core executive deficits, may play a role in verbal memory impairment in adults with ADHD. Concerning treatment implications, future research could probe to what extent external strategy instruction might increase the versatility of mnemonic strategy use in adult ADHD, and thereby partly compensate for their verbal memory deficits.