Nostalgia is known to boost state wellbeing and authenticity for people in the general population. However, little research has explored nostalgia’s benefits outside of the general population. This study had two: (1) to explore music evoked nostalgia and its effects on mood, state wellbeing and authenticity in autistic individuals, a group of people who tend to experience reduced wellbeing, compared to non-autistic individuals and (2) to examine the influence of dispositional rumination and reflection on any benefits gained from nostalgic recollection. 146 autistic (69 diagnosed and 77 who self-identified as autistic) and 174 non-autistic people aged 18–25 took part in an online survey. Participants completed scales measuring autistic traits, rumination and reflection. They also reported their mood before, and their mood, state wellbeing and authenticity after a nostalgia manipulation, in which they either listened to and reflected on a nostalgic or a non-nostalgic song. Music evoked nostalgia (versus control) boosted state wellbeing and authenticity in autistic as well as non-autistic individuals. Results also indicated that people who were prone to reflection versus rumination were more likely to reap wellbeing benefits of engaging in nostalgia. This study is the first to show that music evoked nostalgia boosts state wellbeing and authenticity in autistic as well as in non-autistic individuals. Findings suggest that, depending on individual tendencies towards rumination and/or reflection, nostalgia could be viewed as a positive activity that autistic people could use to support wellbeing, aiding their day to day living in the non-autistic social world.