Objective: Self-reported memory difficulties are common among older adults, but few studies have examined memory problems among autistic middle-aged and older people. The current study examines self-rated prospective (PM) and retrospective (RM) memory difficulties and their associations with age in middle-aged and older autistic and non-autistic people. Methods: 350 autistic people (58% assigned-female-at-birth; age-range: 40-83 years) and 350 non-autistic adults matched on age, birth-sex and education level were included in the analysis. Participants completed the Prospective and Retrospective Memory Questionnaire (PRMQ) which includes questions about PM vs. RM (memory type), environment-cued vs. self-cued (cue), and short vs. long delay (delay). Results: Autistic people reported significantly more PM and RM difficulties than the comparison group. Both groups reported more difficulties with PM (vs. RM), self-cued (vs. environment-cued), and short (vs. long) delay. No significant interactions were observed. Among autistic people, younger age was associated with reporting more PM and RM difficulties, but this pattern was not observed among non-autistic people. Conclusions: Autistic people may be at reduced risk for memory problems as they age, compared to their same-age non-autistic peers. Further studies are required to explore the association between self-reported memory challenges and memory task performance among autistic older people.