Background: This report presents the single case of Jack, a 67-year-old referred to our Older Adult Community Mental Health Team (OA CMHT) for his distressing persecutory delusion and high levels of worry. Jack also reported learning difficulties and autistic traits, although neither were formally diagnosed. Method: Ten sessions of worry intervention taken from The Feeling Safe Programme worry module were used to reduce Jack’s time spent worrying and increase his engagement in meaningful activity. Weekly face-to-face sessions were held, with Jack’s brother acting as a co-therapist. Adaptations to the intervention were made based on Jack’s learning preferences. An AB single case experimental design was adopted to compare Jack’s scores on measures of worry, paranoia and delusional conviction, and wellbeing and daily functioning before and after intervention. Results: Results demonstrate the worry intervention improved Jack’s scores on all measures to a clinically significant degree. Conclusions: This is the first known report of applying the worry intervention to an older adult. The results show the intervention can be of considerable benefit in terms of reducing worry and paranoia, in the context of both older age and suspected neurodiversity.