Engagement in excessive sedentary behaviour represents a health risk for adolescents. The current study aimed to investigate patterns of sedentary behaviour amongst Irish female adolescents aged between 15 and 19 years old. 314 adolescents completed a questionnaire on their sedentary behaviour habits, health behaviours (physical activity, smoking, and alcohol use), enjoyment of sedentary behaviour, value on health, and sedentary facilitators in their home. Parents provided information on parental education, the child's weight and height, and parental sedentary behaviour habits. Cluster analysis found that five distinct sedentary clusters existed in this sample: Unproductive/Social Sedentary, Reading/Productive Behaviours, Mixed Sedentary Interests, Restricted Interests/High Television, and Academic Sedentary. The clusters differed on smoking and alcohol use, enjoyment of sedentary behaviour, and parental engagement in sedentary behaviour. The findings from this study support the use of a socio-ecological framework for investigating the development of sedentary behaviour patterns. (Contains 5 tables and 1 figure.)