Inclusion Criteria:  community-dwelling adults (aged 18 or above) with a confirmed diagnosis of stroke having at least mild symptoms of psychological distress measured by the Depression, Anxiety and Stress Scale having a computer or a smartphone with internet access at home being able to provide informed consent by understanding the nature of study participation  Exclusion Criteria:  living in a nursing home at time of consent a diagnosis of severe cognitive impairment (e.g., dementia) inability to understand spoken and/or written English having severe communication difficulties (e.g., aphasia and dysarthria) that can impede study participation having a life-threatening illness (e.g. advanced cancer or advanced heart failure) that would make survival for 6 months unlikely having a diagnosis of other central nervous system disorders other than stroke or a severe mental illness (e.g., psychosis) currently receiving a psychological therapy or participating in another study that may affect mental health having a prior experience in ACT having psychiatric hospitalizations or diagnoses of mental illness in the previous two years taking antipsychotic medication at the time of recruitment.