Abstract Background The incidence of acute appendicitis in older patients significantly varies from that in younger adults. The coronavirus disease 2019 (COVID-19) pandemic has increased the risk of early post-appendectomy complications (EPAC). This study aimed to investigate the incidence and risk factors associated with EPAC in older patients after appendectomy and to define active COVID-19 infection during surgery as an associated risk factor for EPAC. Methods We conducted a retrospective multicenter analysis of older patients aged ≥ 60 years who underwent appendectomy between April 2020 and December 2024. Logistic regression identified the risk factors associated with EPAC. Results A total of 585 patients aged ≥ 60 years were divided into the EPAC (n = 32) and no EPAC (n = 553) groups. The incidences of EPAC was 5.5% (32/585), including superficial incisional surgical site infections (SSI) (9/32, 28.1%), deep incisional SSI (2/32, 6.3%), organ/space infection (2/32, 6.3%), intra-abdominal abscess (9/32, 28.1%), ileus (2/32, 6.3%), pneumonia (3/32, 9.4%), acute myocardial infraction (MI) (2/32, 6.3%), fecal fistula (2/32, 6.3%), and acute adhesive intestinal obstruction (1/32, 3.1%). Multivariable analysis identified that active COVID-19 infection during surgery (odds ratio (OR) = 25.9; 95% confidence interval (CI) 4.8–139.1; p < 0.001), American Society of Anesthesiologists (ASA) score ≥ II (OR = 4.5; 95% CI 1.2–17.07; p = 0.02), open approach (OR = 30.6; 95% CI 8.1–115.3; p < 0.001), and high-grade appendicitis ≥ IV (OR = 63.06; 95% CI 7.5–526.4; p < 0.001) were significant associated risk factors for EPAC. Conclusions The incidence of EPAC in older patients after appendectomy is 5.5%. Active COVID-19 infection during surgery is strongly associated with an increased risk of EPAC. COVID-19 should be considered in perioperative risk assessment of EPAC.