Early-onset gastric cancer (EOGC) defined as gastric cancer diagnosed in individuals aged ?49 years, represents a distinct and increasingly recognized clinical entity with an aggressive phenotype and poor prognosis. Unlike late-onset gastric cancer, EOGC is often diagnosed at advanced stages and is associated with distinct histopathological and molecular features. This study aims to characterize the demographic, clinical, and molecular characteristics of EOGC in a diverse cohort to elucidate potential risk factors and disease behavior. A retrospective cohort study was conducted on 32 EOGC cases identified from over 400 screened gastric carcinoma patients at Baylor Scott & White Healthcare (2002–2022). Demographic, clinical, and molecular data, including Helicobacter pylori infection, lifestyle factors, histopathology, and biomarkers (HER2, MSI), were analyzed. Among 32 patients diagnosed with EOGC, the median age was 45 years (±7.2), with a slight female predominance (53.1%). Hispanic ethnicity accounted for 41% of cases. The most common risk factors were H. pylori infection (84.6%), elevated BMI (78.1%), and smoking (51.7%). Most tumors were poorly differentiated (87.5%), with signet ring cell carcinoma (SRCC) comprising 43.7% of cases. Advanced-stage disease (III/IV) was present in 59.4% of patients at diagnosis. Tumors were predominantly located in the gastric body (46.9%) and antrum (34.4%). HER2 positivity was observed in 4.2% of cases, while MSI was present in 8.3%. The overall 5-year survival rate was 22.6%, significantly lower in advanced-stage disease (5.9% for stage III/IV vs. 63.6% for stage I/II, p = 0.028). Gender comparisons revealed higher rates of alcohol use and antral tumors in males, while females exhibited more poorly differentiated tumors and gastric body involvement. This study underscores the aggressive nature of EOGC, highlighting advanced-stage presentation, poor survival, and distinct molecular pathways. The high prevalence of H. pylori, obesity, and smoking reinforces the need for targeted prevention. Given its rising incidence and late-stage diagnosis, risk-based screening, optimized treatments, and novel therapeutic strategies are crucial to improving patient outcomes.