Rational design of active and earth‐abundant catalysts toward oxygen evolution reaction (OER) is of particular significance for archiving highly efficient water electrolysis. Herein, a series of perovskite oxide quantum dots with abundant oxygen vacancies adhered on oxidized carbon nanotubes (LaNiXFe1‐XO3‐δ‐QDs/CNTs) were fabricated by simple sol‐gel and pyrolysis methods. The results indicate that the optimized LaNi0.3Fe0.7O2.759‐QDs/CNTs sample with adjust crystal structure, proper ratio of Ni to Fe, and desirable oxygen vacancy concentration shows a low overpotential (0.34 V at 10 mA/cm2), a low Tafel slope (74 mV dec−1), and excellent stability when it was evaluated as OER electrocatalyst. This work will shed light on the development of precious‐metal‐free catalysts with promoted catalytic performance [ABSTRACT FROM AUTHOR]