The qualitative research mainly explored the perceptions of solidarity among young people with local and international volunteering experience, emphasising Lithuania's and Slovakia's cross-national context. Additionally, the study explores the insights and perspectives of youth workers. Through semi-structured interviews grounded in social capital and self-determination theories, it is revealed that young people conceptualise solidarity as a form of collective action, a sense of community, and mutual support. Youth workers define solidarity as mutual assistance, shared responsibility, and equality within inclusive environments. This discussion re-evaluates solidarity as more than belonging; it advocates for youth empowerment and active social transformation and highlights the ethical responsibility of care. The insights from a youth-centred perspective present pragmatic recommendations for practitioners engaged with young individuals, volunteer organisations, and policymakers. This is particularly relevant for those who foster youth engagement and enhance social cohesion.