Pineapple peel contains various nutrients that support the growth of microorganisms. Secondary metabolites are produced during fermentation as antioxidants. Antioxidants are helpful to ward off free radicals in the body. The antioxidants produced by pineapple peel during fermentation can be used as a functional food source. In this study, pineapple peel was fermented using instant yeast. This study aimed to determine fermentation's effect on the antioxidant activity of the pineapple peel. The variety of solvents used in the extraction consisted of methanol and ethanol. The results obtained from this study are the antioxidant activity of fermented pineapple peel methanol extract of 49.54 ± 2.27%. The antioxidant of fermented pineapple peel ethanol extract was 43.59 ± 8.60%. Based on the analysis of polyphenols, the unfermented pineapple peel and fermented pineapple peel contain gallic acid, catechins, and Epigallocatechin gallate (EGCG). The levels of gallic acid, catechins, and EGCG in fermented pineapple peel were 17.24 mg/100 grams, 16.95 mg/100 grams, and 12.67 mg/100 grams. Based on the results of this study, the antioxidant activity of fermented pineapple peel methanol extract was 49.54 ± 2.27%. Meanwhile, the fermented pineapple peel ethanol extract was 43.59 ± 8.60%.