AbstractCu‐based catalysts have been widely applied in electroreduction of carbon dioxide (CO2ER) to produce multicarbon (C2+) feedstocks (e.g., C2H4). However, the high energy barriers for CO2 activation on the Cu surface is a challenge for a high catalytic efficiency and product selectivity. Herein, we developed an in situ *CO generation and spillover strategy by engineering single Ni atoms on a pyridinic N‐enriched carbon support with a sodalite (SOD) topology (Ni‐SOD/NC) that acted as a donor to feed adjacent Cu nanoparticles (NPs) with *CO intermediate. As a result, a high C2H4 selectivity of 62.5 % and an industrial‐level current density of 160 mA cm−2 at a low potential of −0.72 V were achieved. Our studies revealed that the isolated NiN3 active sites with adjacent pyridinic N species facilitated the *CO desorption and the massive *CO intermediate released from Ni‐SOD/NC then overflowed to Cu NPs surface to enrich the *CO coverage for improving the selectivity of CO2ER to C2H4.