Agroindustrial residues have great nutritional potential, and their use is following circular economy practices. The study aimed to evaluate the effect of adding a functional ingredient (FI), produced by drum-drying mango peels (146°C/ 15 s), in a milk chocolate formulation. A standard chocolate formulation (CHS) and another one added with 10% (w/w) of the functional ingredient (CHFI) were processed in a pilot plant through the following steps: mixing, coaching, refining, tempering, molding/vibrating, cooling, and demolding. The following analyzes were carried out by standard methods: moisture content, water activity, antioxidant capacity (DPPH, ABTS), total phenolics, dietary fiber, carotenoids, and minerals. Moisture contents differed significantly (p≤0.05), with 1.35% in CHS and 2.16% in CHFI. The means of water activity did not differ statistically (p>0.05), being 0.38 in CHS and 0.40 in CHFI. There was an increase in the phenolic content (approx. 30%), with 567 mg EAG/100 g d.b. in CHS and 725 mg EAG/100 g d.b.in CHFI. An increase in antioxidant capacity (approx. 40%) was observed, with 34.97 (DPPH) and 46.5 0 (ABTS) µmol TE/ g d.b. in CHS, and 48.72 (DPPH) and 65.97 (ABTS) µmol TE/g d.b. in CHFI. Not detected in the standard formulation, the contents of carotenoids in CHFI resulted in 970.0 and 203.82 µg/100 g d.b. of total carotenoids and β-carotene, respectively. The total fiber content doubled with the insertion, from 2.51 to 5.08 g / 100 g d.b., and the soluble fiber / total fiber ratio went from 13 to 37%, which is nutritionally more interesting. The addition of the FI also promoted significant increases (p≤0.05) in the levels of calcium, magnesium, manganese, and potassium. The study demonstrated the technical feasibility of using the ingredient developed from mango peels in a milk chocolate formulation, resulting in important nutritional gains.