The purpose of this research was to examine the dimensionality and targets of the commitment of volunteers (including committee members, coaches, officials, and volunteers in various other roles) in junior sport organisations, and the links between commitment and behavioural outcomes, specifically, intention to stand down from a volunteer role, intention to cease volunteering for the club or centre, and self-assessed performance. A sequential explanatory mixed methods design consisting of a quantitative (two studies) and a qualitative phase (one study) was employed. Drawing on Meyer and Herscovitch’s (2001) general commitment model, the quantitative studies assessed commitment to three organisational targets: the organisation (defined as the centre or the club), the team of volunteers, and the volunteer role. Participants were recruited from Little Athletics centres in New South Wales (Metropolitan Region) for the first study. Survey instruments were distributed to volunteers during a regional championship with 27 participating centres. One hundred and nine surveys were completed and returned. The data were subjected to reliability analyses and then analysed with techniques such as correlations, t-tests and ANOVAs. This study found that volunteers had distinctive affective commitments to the three targets assessed. The second study, building on the findings of the first one, refined the survey measures and also examined intention to stand down from the volunteer role, intention to cease volunteering for the club or centre, and self-assessed performance. Participants were recruited from Little Athletics centres in Queensland. Survey instruments were mailed to all 120 centres. Two hundred and four surveys from participants representing 52 centres were completed and returned. The data were analysed with Partial Least Squares modeling (PLS), stepwise regression, and logistic regression. This study found that volunteers held distinctive affective and normative commitments to the three targets, and that each target was related to a behavioural outcome. Specifically, organisational commitment and commitment to the role were related to self-assessed performance, commitment to the role was related to intention to stand down from the volunteer role, and commitment to the team of volunteers was related to intention to cease volunteering for the centre or club. The study also showed that committee members had a stronger commitment than volunteers in other roles, and that volunteers without children (or without children currently enrolled in the volunteers’ respective centres) had a stronger commitment than volunteers with children. Volunteers with more experience, particularly those with four or more seasons of experience, had significantly stronger commitment than volunteers with less experience...