El Niño‐Southern Oscillation (ENSO) is the most pronounced interannual variability over the tropical Pacific, exerting profound influences on global climate. In the mid‐latitude Northeast Pacific (NEP), persistent sea surface temperature anomalies (SSTAs) have attracted wide attention in recent decades and have
been linked to tropical variability. Considering their important climate impacts and potential linkages, this study investigates the non‐stationary relationship between SSTAs in the NEP (SSTANEP) and ENSO using correlation decomposition and Linear Inverse Modeling. Our analysis reveals notable shifts in the SSTANEP‐ENSO linkage during 1961–2022. Before 1980, SSTANEP exhibited minimal influence on ENSO evolution. Conversely, during 1981–2000, SSTANEP substantially contributed to ENSO development, primarily via the North Pacific Meridional Mode. However, after 2000, this relationship has weakened again, suggesting a complex interplay between SSTANEP and ENSO. Understanding these relationship shifts is essential for advancing ENSO predictability and thereby enhancing the reliability of seasonal‐to‐decadal climate prediction.