Candidate selection and campaigning are two important political processes, which occur within a political party. Following decisions made with regards the two processes, potential tensions may arise between the local members and the National Headquarters of a political party, which possess side effects. This thesis will investigate how candidate selection and campaigning processes, have transformed on the island of Ireland, taking into consideration first order (UK General Election, Northern Ireland Assembly elections and Dáil election) and second order elections (local election). An all-island study, it aims to encompass a mixed methodological approach, through a critical realism framework, to firstly, examine trends through quantitative methods including spatial data analysis, and secondly, investigate the trends through qualitative methods, to understand the experiences that emerge from the trends, through semi-structured interviews and documentary analysis. By analysing candidate selection trends, it can be determined who are, or are not, selected by political parties, and how have these trends changed, dependent on the election, electoral system, cultural processes, or by formal/informal structural rules. Furthermore, relations between the actors are examined, and how these relations can impact a campaign. This thesis identified that representation of under-represented groups is increasing, supported by structural mechanisms and increased participation of the relevant groups. However, this increase has occurred, predominately in urban regions, and cultural issues still exist, which have created issues for candidates and political parties. The importance of traditional forms of campaigning is established, but the growing use of modern forms has increased the demands placed on representatives, but also the abuse experienced on this medium, has increased difficulties with recruitment. Finally, the importance of geography is identified, through the ‘friends and neighbours’ effect, urban-rural dimension, and the overall attachment to a place, namely Agnew’s (2002) sense of place. Through a mixture of exploratory data analysis, including geospatial data analysis, and qualitative methods, a range of trends and observations are identified, with potential solutions to these issues suggested, in this cross-border elections analysis.