Background: The World Cancer Research Fund (WCRF)/American Institute for Cancer Research (AICR) Cancer Prevention Recommendations are lifestyle-based guidelines which aim to reduce cancer risk. This study investigated, in the UK Biobank, associations between an abbreviated score to assess adherence to these Recommendations and the risk of all cancers combined and of 14 cancers for which there is strong evidence for links with diet, adiposity, and physical activity. Methods: We used data from 288,802 UK Biobank participants (mean age 56.2 years), cancer-free at baseline. An abbreviated version of the 2018 WCRF/AICR Score was calculated to assess adherence to five Recommendations on (i) body weight, (ii) physical activity, (iii) fruits, vegetables, and dietary fiber, (iv) red and processed meat, and (v) alcohol. Multivariable Cox proportional hazards models were used to analyze associations between the abbreviated score (range, 0–5 points) and cancer incidence, adjusting for confounders. Results: During a median follow-up of 8.2 years (interquartile range, 7.4–8.9), 23,448 participants were diagnosed with cancer. The abbreviated score was inversely associated with risk of cancer overall [HR: 0.93; 95% confidence interval (CI): 0.92–0.95 per 1-point increment], and breast (HR: 0.90; 95% CI: 0.87–0.94), colorectal (HR: 0.86; 95% CI: 0.83–0.90), lung (HR: 0.89; 95% CI: 0.84–0.94), kidney (HR: 0.83; 95% CI: 0.76–0.90), pancreatic (HR: 0.86; 95% CI: 0.79–0.94), uterine (HR: 0.79; 95% CI: 0.73–0.86), esophageal (HR: 0.82; 95% CI: 0.75–0.90), stomach (HR: 0.89; 95% CI: 0.79–0.99), and liver (HR: 0.80; 95% CI: 0.72–0.90) cancers. Conclusions: Greater adherence to the Cancer Prevention Recommendations, assessed using an abbreviated score, was associated with reduced risk of all cancers combined and of nine site-specific cancers. Impact: Our findings support compliance to these Recommendations for cancer prevention.