Background: A total of 1.5% to 20.2% of total joint arthroplasty patients experience delirium. Until now, no formal systematic review or meta-analysis was performed to summarize the risk factors of delirium after primary total joint arthroplasty (TJA). Methods: A comprehensive search encompassing Medline, Embase, and the Cochrane central database was conducted, incorporating studies available up to June 2023. We systematically reviewed research on the risk factors contributing to delirium following TJA in elderly patients, without language restrictions. The methodological quality of the included studies was evaluated using the Newcastle–Ottawa Scale. Data synthesis through pooling and a meta-analysis were performed to analyze the findings. Results: A total of 23 studies altogether included 71,095 patients with primary TJA, 2142 cases of delirium occurred after surgery, suggesting the accumulated incidence of 3.0%. The results indicated that age, current smoker, heavy drinker, mini-mental state examination score, hypertension, diabetes mellitus, chronic kidney disease, history of stroke, coronary arterial disease, dementia, history of psychiatric illness, American Society of Anesthesiologists physical status III–IV, general anesthesia, anesthesia time, operative time, intraoperative blood loss, blood transfusion, β-blockers, ACEI drugs, use of psychotropic drugs, preoperative C-reactive protein level, and preoperative albumin level were significantly associated with postoperative delirium after primary TJA. Conclusions: Related prophylaxis strategies should be implemented in the elderly involved with above-mentioned risk factors to prevent delirium after primary TJA.