To date, microRNA‐4709 (miR‐4709) has not been studied in colon adenocarcinoma (COAD) on the basis of experiments. In our study, we aimed to investigate the biological roles and clinical significance of miR‐4709 in COAD. The expression difference between miR‐4709 and NR3C2 was measured based on The Cancer Genome Atlas database and cells. Kaplan‐Meier and logrank tests were applied to determine the overall survival (OS) differences according to the miR‐4709 and NR3C2 expression levels. To measure whether the miR‐4709 level was associated with COAD cell growth, migration, and invasion, we respectively conducted 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide, wound healing, and transwell assays. A luciferase reporter assay was applied to confirm the relationship between miR‐4709 and its predicted target. High expression of miR‐4709 was found in COAD tissues and cells. The OS rate in the miR‐4709 low expression group was significantly higher than that in the miR‐4709 high expression group. Univariate and multivariate analyses exhibited that miR‐4709 expression was an independent adverse prognostic factor. Exogenous miR‐4709 overexpression promoted proliferation, migration, and invasion of LOVO and SW480 cells. Bioinformatics analysis and luciferase assay demonstrated that miR‐4709 directly binds to the 3′‐untranslated region of NR3C2. NR3C2 was lowly expressed in COAD and high expression of NR3C2 had a better prognosis compared with that in the low expression of NR3C2. Correlation analysis showed that there is a close association between the level of expression of NR3C2 and miR‐4709. Accordingly, miR‐4709 may function as an oncogene in COAD and provide a preclinical proof for candidate management to target new miR‐4709‐NR3C2 signaling for COAD therapy.