Background. Cancer diagnosis is a complex and multifaceted process that can be stressful and anxiety-provoking for patients. Evidence-based tools and information aids that can be used for guiding and supporting patients during cancer investigations and after diagnosis are limited. This paper presents a user-centred codesign project that aims to develop a cancer pathway support tool for patients, carers, and healthcare professionals. Method. A mixed-method codesign approach was used including prototype development (January–March 2022), three online codesign workshops (April–June 2022), one-to-one feedback, and beta testing informed by the standardised Theoretical Framework of Acceptability (TFA) questionnaire (July–October 2022). Nine individuals with lived experience of cancer contributed to the project and are referred to as codesigners. Results. The codesigners valued the potential importance of a tool that can be used by the patients and carers if they want specific information about cancer investigations, diagnosis, and treatment. The ability to select what they need as opposed to long leaflets and generating their own questions for the healthcare providers were highlighted as important aspects of improving patient care. The tool was collectively designed to provide clear definitions of the cancer care pathway and easily accessible links from trusted resources and includes practical information to minimise the burden that can be experienced from preparation for appointments and tests. Beta testing results with a small sample of potential users including patients, carers, and healthcare providers (n = 23) showed high acceptability of the guide (range = 7–35, mean = 28.52, and standard deviation = 3.88) based on the TFA questionnaire. Conclusion. A cancer pathway support tool called “Your Cancer Pathway Support Guide (YCPSG)” was developed as a result of an iterative codesign process aiming to improve patient experience and outcomes for people referred on a suspected cancer pathway or who have been diagnosed with cancer. The tool provides information and support in both digital and PDF formats. Further studies are needed to evaluate the potential impact of “Your Cancer Pathway Support Guide” on patient outcomes and experience and the wider system.