81 Background: Colorectal cancer (CRC) is a significant global health concern, with a rising incidence of early-onset cases in individuals under 50. This trend may be influenced by various factors, including metabolic syndrome (MetS), obesity, dietary habits, and lifestyle choices. However, the impact of changing MetS status on the risk of early-onset CRC remains understudied. Methods: A total of 3,340,635 Korean national insurance beneficiaries that received two consecutive biennial mandatory health exams (2009–2011) were followed-up until 2019. Participants were categorized into MetS-free, recovered, developed, or persistent groups. The study assessed CRC risk patterns associated with these MetS dynamics, considering factors like age, sex, smoking, alcohol consumption, exercise, and income status. Results: Among 20-39-year-olds, those with persistent MetS had a 16% higher risk of CRC (adjusted hazard ratio [aHR] 1.16; 95% CI, 1.00–1.33) compared to MetS-free individuals. Furthermore, persistent MetS was associated with a 29% higher risk of rectal cancer in this age group, while recovery from MetS also increased rectal cancer risk by 28%. Among 40-49-year-olds, the MetS-persistent group had a 22% higher risk of CRC (aHR 1.22; 95% CI, 1.14-1.30), with a 34% higher risk of distal colon cancer, while those who developed MetS showed a 26% higher risk of CRC compared to the MetS-free group. Conclusions: This study highlights that the persistence of MetS in young adults is associated with an increased risk of early-onset CRC. The findings suggest that managing MetS in young individuals through lifestyle modifications, such as weight reduction and regular exercise, could be beneficial in reducing the risk of early-onset CRC.