Endoplasmic reticulum stress (ERS) has been implicated in the pathogenesis of various cancers, including colon cancer, by regulating tumor cell survival, growth, and immune response. However, the specific genes involved in ERS that could serve as prognostic markers in colon cancer remain underexplored. This study aims to identify and validate endoplasmic reticulum stress related genes (ERSRGs) in colon cancer that correlate with patient prognosis, thereby enhancing the understanding of ERS in oncological outcomes and potential therapeutic targeting. We utilized bioinformatics analyses to identify ERSRGs from publicly available colon cancer datasets. Differential expression analysis and survival analysis were performed to assess the prognostic significance of these genes. Validation was conducted through quantitative real-time PCR (RT-qPCR) on selected colon cancer cell lines. Our study identified nine ERS related genes (ASNS, ATF4, ATF6B, BOK, CLU, DDIT3, MANF, SLC39A14, TRAF2) involved in critical pathways including IL-12, PI3K-AKT, IL-7, and IL-23 signaling, and linked to 1-, 3-, and 5-year survival of patients with colon cancer. A multivariate Cox model based on these ERS related genes demonstrated significant prognostic power. Further, TRAF2 strong correlated with immune cells infiltration, suggesting its potential roles in modulating immune responses in the tumor microenvironment. The RT-qPCR validation confirmed the differential expression of these genes in human colon cancer cell lines versus human normal colonic epithelial cell line. The identified ERSRGs could serve as valuable prognostic markers and may offer new insights into the therapeutic targeting of ERS in colon cancer.