Introduction: Infection with SARS-CoV-2 virus may result in long COVID, a syndrome characterized by symptoms such as dyspnea, cardiac abnormalities, cognitive impairment, and fatigue. One potential explanation for these symptoms is adrenal insufficiency (AI). Objective: To evaluate the prevalence of AI in patients with a history of COVID-19 pneumonia. Methods: Cross-sectional study of patients who were aged ≥ 18 years and had a 3-month history of radiography-confirmed COVID-19 pneumonia. Exclusion criteria included current or previous treatment with glucocorticoids and use of an oral contraceptive. Adrenal function was evaluated using a low dose (1ug) corticotropin stimulation test (CST). Serum cortisol levels were measured at 0, 30, and 60 minutes, and baseline plasma ACTH was also measured. Results: Of the 41 patients enrolled, the median age was 62 years, 17 (42%) were female, and all 41 (100%) had severe pneumonia at baseline. Eleven patients (27%) had AI, as evidenced by hypocortisolism (mean serum cortisol 198.92 nmol/L, standard deviation 83.87, range 84.15–289.42). Of these 11 patients, 10 (91%) had secondary AI (median ACTH 6.27 pmol/L, range 4.98–9.95 pmol/L) and one had primary AI (mean ACTH 32.78 pmol/L). Six of the 11 patients with AI (54.5%) reported symptoms of persistent fatigue and 5 (45.5%) required regular glucocorticoid replacement. Conclusions: Our results suggest that AI, predominantly caused by pituitary disruption, may emerge after SARS-CoV-2 infection and should be considered in patients with a history of COVID-19 pneumonia with or without clinical hypocortisolism.