Purpose <p>Service evaluation comparing the effectiveness and acceptability of an in-person and a digitally delivered acceptance and commitment therapy (ACT)–based group programme for fear of cancer recurrence (FCR) for breast cancer survivors.</p> Methods <p>The programme was designed and delivered as part of a real-world, supportive care intervention and adapted for digital delivery in response to COVID-19 pandemic restrictions. FCR, quality of life (QoL), psychological flexibility, and psychological distress measures were routinely collected pre-participation, post-participation, and 12 weeks following completion.</p> Results <p>Ninety-seven in-person and 61 digital participants completed the group programme. Uptake was 30% and retention 89% for in-person. Uptake was 23% and retention 64% for online referrals.</p> <p>Between group statistical analyses revealed non-significant differences between delivery modality on overall scores of FCR (<i>p</i> = 0.76), QoL (<i>p</i> = 0.06) and psychological distress (anxiety <i>p</i> = 0.16; depression <i>p</i> = 0.22). There was a significant difference in psychological flexibility scores (<i>p</i> = 0.04); digital participant scores were higher (mean = 83) than in-person participants (mean = 76.3). Within-group statistical analyses found a significant effect of time for all outcome measures, with a significant decrease in FCR and psychological distress and a significant increase in QoL and psychological flexibility (<i>p</i> &lt; 0.001 for all measures). There were no statistically significant interaction effects between delivery modality and timepoint.</p> Conclusion <p>In-person and online delivery of a real-world FCR group programme offered to breast-cancer survivors was found to be beneficial and comparable. These results support the potential benefits of a flexible approach to delivery modality of supportive care interventions. Further investigation is required to determine if these results are replicable within diverse populations.</p>