The design of cost‐effective and highly efficient electrocatalysts for oxygen evolution reaction (OER) remains a key element in pursuit of developing sustainable renewable energy conversion and storage systems. Herein, we report the fluoride perovskite series (KNi_xCo_1-xF₃) as a promising OER catalyst. The fluoride perovskites with merits of strong M-F polarized (M=Co, Ni) bond is beneficial for surface reconstruction of oxy-hydroxide (M-O/MOOH) catalytic active phase, which is the rate determining step in the OER reaction. The designed catalyst composition of KNi_0.8Co_0.2F₃ (KNCF82) exhibits an outstanding OER activity, with a smaller Tafel slope and higher OER activity than state-of-art commercial RuO₂.