Digital innovations are transforming cultural tourism, providing opportunities for sustainable development and enhanced visitor experiences. This scientific paper examines the “MUSEUMS 4 YOU” project as a case study, highlighting how a unified digital ticket contributes to the development of sustainable cultural tourism in Belgrade. The project was implemented through the collaboration of the Republic Secretariat for Public Policies, the Ministry of Culture, the Ministry of Tourism and Youth, the Tourist Organization of Belgrade, four museums, with the support of GIZ and the Design Thinkers Academy. The project’s goals include increasing museum accessibility, enhancing the tourist offer, and reducing the ecological foot print. The research adopts a qualitative approach, applying the Design Thinking methodology to a small sample. Data were collected through focused interviews with key project stakeholders and surveys of museum visitors. The findings indicate that the unified ticket contributes to increased museum attendance, strengthened collaboration among cultural institutions, and the development of a sustainable tourism product while identifying technical and promotional challenges in implementation. The paper concludes by emphasizing the potential of digital services, such as the unified ticket, to improve the sustainability and appeal of cultural tourism. Recommendations include improving digital solutions, more effective promotion, and expanding the model to other cultural institutions across Serbia.