Butterfly pea flower is rich in phenolic and flavonoid antioxidants that protect the skin from free radicals, which can lead to oxidative damage. This study aimed to optimize a lotion formulation containing butterfly pea flower extract (BPFE), using triethanolamine (TEA) and stearic acid as emulsifiers, and to evaluate its antioxidant activity. Eight lotion formulations were prepared using the Simplex Lattice Design method (Design Expert v13.0), focusing on optimizing the stearic acid to TEA ratio. Antioxidant activity was measured using DPPH (2,2-diphenyl-1picrylhydrazyl) at a wavelength of 516 nm. Key parameters such as spreadability, adhesion, pH, and viscosity were assessed. The maceration method yielded BPFE with a 49.66% extraction efficiency. The optimized formulation demonstrated a spreadability of 6.26±0.38 cm, adhesion of 3.2±0.2 s, a pH of 7.19±0.005, and a viscosity of 120 dPas. Both BPFE and the optimized lotion formulation exhibited strong antioxidant activity, with IC50 values of 59.87±0.802 µg/ml and 84.52±1.418 µg/ml, respectively. The optimized BPFE lotion formulation presents promising potential for development as a cosmeceutical product.