Background: Colorectal neoplasia and diverticulosis are common findings on colonoscopies. While adenomas are precursors to colorectal cancer, diverticulosis is usually asymptomatic but can lead to diverticulitis. Despite their prevalence and coexistence, the relationship between these conditions remains unclear. This study investigates whether diverticulosis is associated with adenomas, considering shared risk factors and potential inflammation-driven mechanisms. Methods: We examined 6154 asymptomatic individuals undergoing colorectal cancer screening in Austria. Diverticulosis and colorectal neoplasia were documented during screenings based on macroscopic definitions. Advanced neoplasia was defined as polyps >1 cm or high-grade dysplasia. Associations between diverticulosis and neoplastic findings were assessed using univariate and multivariable logistic regression models. Results: Although the overall incidence of any polypoid lesion was higher in the diverticulosis group (37% vs. 30%), statistical analysis revealed a comparable rate of advanced neoplasms in both groups. Importantly, no significant link between diverticulosis and advanced neoplasms was found (OR 1.125; 95% CI: 0.933 to 1.357, p = 0.218) even after adjusting for confounding factors. In a univariate analysis, a statistically significant association between diverticulosis and the presence of any colorectal polyps was identified (OR 1.388; 95% CI: 1.244–1.549, p < 0.0001). However, after adjusting for confounding factors in model 2 (OR 1.065, 95% CI: 0.942 to 1.204, p = 0.314) and model 3 (OR 1.071, 95% CI: 0.925 to 1.239, p = 0.360), this effect was also not statistically significant. Conclusions: Patients with diverticulosis share demographic and clinical features with those at risk of colorectal neoplasia, such as older age, male gender, and higher cardiometabolic risk. However, diverticulosis does not independently increase the risk of advanced colorectal neoplasia or unspecified polypoid lesions.