The conversion of agro-industrial waste into value-added products has attracted the attention of the scientific community. Pectin is an extensively used by-product of agricultural waste and has many applications. The present research used pomegranate peel for the extraction of pectin and explored its antioxidant properties. Pectin from Punica granatum peel was extracted with the help of a feasible, low-cost, and ecofriendly acidified extraction method using ethanol as an extraction solvent. The yield of the pectin with ethanol was found to be 19.1%. The extracted pectin was chemically modified using the amidation method. The structural characterization of the extracted and modified pectin was carried out using the SEM (for morphology), FTIR (for chemical bond and functional groups), EDX (for an elemental analysis), and XRD (for crystallinity) techniques. After confirming the modification of pectin, both the native and modified pectin were assessed for their antioxidant potential. The antioxidant properties of natively extracted pectin and modified pectin were evaluated against different types of free radicals with the help of a hydroxyl radical antioxidant assay, a DPPH radical scavenging assay, ferric-reducing antioxidant power, and a phosphomolybdenum assay. All the performed antioxidant assays revealed that the antioxidant activity of pectin was increased after modification through amidation. The findings could be very useful in obtaining pectin from the peel waste of Punica granatum and obtaining pectin with more bioactive potential via its chemical modification through an optimized method. This is also a step forward in achieving the goal of a sustainable environment. This study contributes to sustainable development by making use of the wasted peels of pomegranate and extracting bioactive pectin at the same time.