Background: Previous research has identified an increased risk of suicide among cancer patients, however this has not been investigated at a population level in England. Those subgroups of patients most at risk need to be identified to ensure appropriate access to psychological support. Aim: To examine the variation in suicide risk among individuals diagnosed with cancer in England. Methods: We identified 4,453,547 individuals (21 million person-years at risk) aged 18 to 99 years at diagnosis of cancer during 1995 to 2015 from the national cancer registry, and followed them up until 31 August 2017. The outcomes of interest were both suicide and open verdicts (ICD-10 X60-X84, Y87.0, Y10-Y34 [excluding Y33.9, Y87.2]). Population-based expected deaths were as published by ONS [2]. We calculated standardized mortality ratios (SMRs) and absolute excess risks (AERs), and explored variation in suicide risk by cancer type, age at death, sex, deprivation, ethnicity, and years since cancer diagnosis. Results: 2352 cancer patients died by suicide. This was 0.08% of all deaths. The overall SMR for suicide was 1.19 (95% CI 1.14-1.24) and AER per 10,000 person-years was 0.18 (0.13-0.22). The risk was highest among individuals diagnosed with mesothelioma, with a 4.34-fold risk corresponding to 4.00 extra deaths per 10,000 person-years. This was followed by pancreatic (3.94-fold), esophageal (2.53-fold), lung (2.52-fold), and stomach (2.14-fold) cancer (all significantly elevated). Suicide risk was highest in the first 6 months following cancer diagnosis (SMR: 2.64 [2.42-2.89]), but a significantly increased risk persisted for 2 years (SMR: 1.21 [1.08-1.35]). Conclusion: Despite low numbers, the elevated risk of suicide in patients with certain cancers is a concern, representing potentially preventable deaths. The increased risk in the first 6 months after diagnosis, which is consistent with previous studies, highlights unmet needs for psychological support delivered alongside cancer diagnosis and treatment. Our findings suggest a need for improved risk stratification across cancer services, followed by targeted psychological support.