Background Receipt of adjuvant therapy for gallbladder adenocarcinoma (GBAC) is associated with a survival benefit. This study sought to identify whether delays in initiation of adjuvant therapy among patients with resected GBAC impacts long‐term survival. Methods Patients with stage II and III GBAC who underwent a curative‐intent resection followed by adjuvant chemotherapy or chemoradiation between 2004 and 2017 were queried from the National Cancer Data Base. Descriptive statistics and multivariate models were constructed to determine the relationship between timely (<12 weeks) and delayed (>12 weeks) adjuvant therapy and overall survival (OS). Results A total of 871 patients with GBAC were identified. The median time to receipt of adjuvant chemotherapy was 67 days and the median time to receipt of adjuvant chemoradiation was 69 days. After controlling for all factors, treatment at an Academic/Research center was the only variable associated with timely receipt of adjuvant therapy. However, after controlling for clinically relevant factors, the timing of adjuvant therapy did not impact OS (delayed: HR 0.93, 95% CI: 0.46‐1.85; P = .83). Conclusion Current guidelines support the use of adjuvant therapy following resection of GBAC. This national cohort study demonstrates that delays in adjuvant therapy >12 weeks did not impact long‐term survival.