Aim This study aimed to investigate the effects of repeated detection of non‐alcoholic fatty liver disease (NAFLD) on the incidence risk of type 2 diabetes in young adults. Materials and Methods In this nationwide population‐based observational study using data from the Korean National Health Insurance Service, approximately 1 125 015 young adults aged 20‐39 years who underwent health screening four times between 2009 and 2013 were included. NAFLD was defined as a fatty liver index (FLI) of ≥60. Repeated detection of NAFLD scores was defined as the number of times the participants met the criteria for NAFLD (0‐4). To account for the degree of repeated detection of NAFLD, weighted repeated NAFLD scores were scaled as a sum by assigning points (0 points for FLI <30, 1 point for 30 ≤ FLI < 60, and 2 points for FLI ≥60) ranging from 0 to 8 points. Results The multivariable‐adjusted hazard ratios of type 2 diabetes associated with repeated detection of NAFLD scores of 1, 2, 3 and 4 were 2.74 (95% confidence interval 2.57‐2.921), 3.45 (3.221‐3.694), 4.588 (4.303‐4.892) and 6.126 (5.77‐6.504), respectively. The incidence risk of type 2 diabetes increased significantly with repeated detection of the NAFLD score. In the analysis of the weighted repeated NAFLD score, the hazard ratios for the incidence of type 2 diabetes showed a significant continuous positive linear association with increasing scores. Conclusions Repeated detection of NAFLD influenced the incidence risk of type 2 diabetes in young adults, and a higher degree of repeated detection of NAFLD was independently associated with the risk of type 2 diabetes in young adults.