This thesis investigated the experiences of children who have a parent with a mental illness, using qualitative methods. It is divided into three separate sections, the first two written as standalone journal papers. Paper 1 is a systematic review and synthesis of qualitative studies exploring children‟s experiences of having a parent with a mental illness. The review used specific databases, a search of qualitative journals and a general internet search to identify relevant studies, and the subsequent application of inclusion/exclusion criteria and a quality appraisal assessment. 14 studies meeting inclusion and quality criteria were identified exploring the experiences of 163 children and young people aged between 5 and 22 years, from a range of countries, with a variety of parental mental health diagnoses. The review then involved synthesising the findings of these studies to generate five overarching themes which were found to influence children‟s experiences. Children who had some knowledge and understanding of their parent‟s mental illness were more likely to use effective coping strategies, have a more positive relationship with their parent, and experience fewer negative effects on them as a child.Paper 2 is an original research study which explored the experiences of children who have a parent with bipolar disorder, to see how this might impact on the child‟s emotional wellbeing. This qualitative study used "In My Shoes‟, a computer assisted interview tool, to explore the experiences of ten children from England aged between 4 and 10 years. Subsequent comparison with their parent‟s accounts enabled greater insight into family life. Child and parent interview data was analysed using thematic and content analyses. The four main themes that emerged from the child interviews were: knowledge and awareness of bipolar disorder; perception of parents; managing family life with a "bipolar‟ parent; and living in a family with bipolar disorder. The study concluded that further research was needed to understand children‟s perspectives, which should be taken into account when developing appropriate services and interventions to support children and parents with mental illness, including bipolar disorder.Finally the third section of the thesis was a critical appraisal of the literature review, research study and research process as a whole, including methodological reflections, implications for future research and clinical practice, and the researcher‟s personal reflections in undertaking the research. The findings were deemed vitally important for the future of families in which a parent has bipolar disorder.