<p>The Beacon Decision Support System (DSS) is a digital platform developed under the EU-funded BEACON project to address disparities in cancer care across Europe. It aims to provide patients, clinicians, researchers, and policymakers with centralized, validated access to oncology information. To evaluate the usability and acceptability of the Beacon DSS, we used a complementary qualitative and quantitative evaluation consisting of two independent studies aimed at informing the iterative development of a patient-centered and stakeholder-relevant tool. Study 1 involved qualitative interviews with 10 participants (five cancer patients and five oncology professionals/researchers) to assess usability, barriers, and expectations. Study 2 used a quantitative survey administered to 45 stakeholders, combining the System Usability Scale (SUS) and AttrakDiff Mini to assess functional and experiential aspects of usability. Patients appreciated the DSS’s visual clarity but reported technical issues such as app freezing and language accessibility, which were promptly resolved and did not persist in subsequent use. Professionals valued resource credibility but noted limitations in search specificity and data coverage. SUS scores (M = 60.3, SD = 9.6) indicated acceptable usability. AttrakDiff results showed strong scores for pragmatic quality and overall attractiveness, but more modest scores for hedonic quality. Feedback led to enhancements, including better filtering, glossary links, language geolocation, and onboarding tutorials. The Beacon DSS is perceived as a useful and credible tool for improving oncology navigation. Addressing usability challenges, particularly in personalization, search logic, and content accessibility, may further enhance the platform’s usefulness and accessibility for a broad range of users.</p>