Youth will be dealing with the global sustainability challenge that our world is currently facing. They are considered to play a crucial role as future leaders in the transition towards a more sustainable society. These leaders need an inherent understanding of the sustainability challenge that they are confronted with. This research explores how sustainability practitioners can use Theory U in order to help younger generations approach sustainability. Both the Framework for Strategic Sustainable Development (FSSD) and Theory U informed this research as they use a systems thinking approach to deal with complexity. A qualitative research approach was chosen, and sixteen semi-structured interviews were conducted. The results revealed seven overarching themes around youth, youth and sustainability, and using Theory U with youth. The findings suggest that Theory U can support sustainability practitioners in working with youth as it offers a strong systems thinking approach, personal development, and connectedness for youth. Complementary with the FSSD’s rigorous approach to sustainability, Theory U offers great potential to youth and sustainability that is yet untapped. In equipping youth at an early age with leadership skills, capacities, and a wider awareness, Theory U can plant the seeds for future sustainability leaders to grow.