The bioactive compounds of Artemisia annua have been used as feed supplements due to their pharmacological activities. Recently, they were also proven to be additives to improve fish performance. The present study is part of a comprehensive investigation to analyze the use of the alcoholic extract of A. annua (ae-Aa) as a nutritional supplement to support sustainable aquaculture. The present study analyzed the effect of short-term dietary supplementation on resistance and health condition of Nile tilapia (Oreochromis niloticus) to evaluate a strategy for using ae-Aa in fish feed. Therefore, juvenile fish from a commercial fish farm (200 fish, 30.43 ± 0.54g) were distributed in 10 tanks (400 L, 20 fish/tank) and fed either with a control diet (ae-Aa free) or a diet containing 0.5% of ae-Aa for 15 days. Subsequently, 10 fish per treatment (2 fish per tank) were used to obtain blood and liver samples. We observed that short-term feed supply with ae-Aa was relevant to improve overall fish condition and productive performance. The short-term ae-Aa supplementation affected the fish immune system by increasing the number of leukocytes (41%), the leukocyte respiratory activity (21%), and the serum concentration of lysozyme (24%). These effects did not interfere with blood cell counts or affect oxygen-carrying capacity. Although glucose and chloride levels remained stable, ae-Aa reduced cortisol levels (-27%). Additionally, ae-Aa short-term feed supply influenced the hepatic antioxidant system by increasing CAT (77%), GPx (69%), GST (45%), and GSH (56%) activity and decreasing hepatic levels of LPO (-38%) and DNA damage (-21%). Furthermore, the ae-Aa short-term supplementation caused an increase in the intestinal villus area and improved growth causing a 17% increase in body mass and 2% in body length. Therefore, we suggest that short-term ae-Aa supplementation may be relevant to enhance fish health conditions and productive performance.