Person-centred planning (PCP) puts individuals with an intellectual disability at the centre of service and support planning, identifying how individuals wish to live their lives and what is needed to make that possible. PCP has been identified as having the potential to facilitate improved social inclusion and community participation. A mixed-methods approach combined quantitative analyses with qualitative case studies of individuals with severe-profound intellectual disability to assess the impact of PCP on community participation for adults with an intellectual disability at a disability service in Dublin. We conclude that PCP may provide a good basis to plan community participation and, with the right supports in place, may provide opportunities for people with complex needs to improve their community participation. Supports including familiar staff and family are critical to the success of PCP for people with complex needs, and their absence may undermine the best intentions of PCP for this population.