The development of low‐Pt catalysts with high activity and durability is critical for fuel cells. Here, Pt‐skin wrapped sub‐5 nm PtCo intermetallic nanoparticles are successfully mounted on single atom Co‐N‐C support by exploiting the barrier effect of Co‐anchor. According to a collaborative experimental and computational investigation, the increased oxygen reduction reaction activity of PtCo/Co‐N‐C arises from the direct electron transfer from PtCo to Co‐N‐C, and the resulting optimal d‐band center of Pt. Owing to such unique electronic structure interaction and synergistic effect, the specific and mass activities of PtCo/Co‐N‐C are up to 4.20 mA cm−2 and 2.71 A mgPt−1, respectively, with barely degraded stability after 40 000 CV cycles. The PtCo/Co‐N‐C also exhibits outstanding activity as an ethanol electrocatalyst. This work shows a new and effective route to boost the overall efficiency of direct ethanol fuel cells in acidic media by integrating intermetallic low‐Pt alloys and single atom carbon support.