Twenty‐nine years of tide‐gauge data are analyzed in conjunction with wind and satellite‐derived sea‐surface height and ocean velocity data to study the interannual and seasonal variations of the Kuroshio transport off the northeastern coast of Taiwan. The data reveals an interannual variation of ±0.1 m (transport‐variation of approximately ±3.5 Sv; 1 Sv = 106 m3 s−1), and a much weaker (5–10 times weaker) seasonal fluctuation that is minimum in May and maximum in November. The interannual fluctuations are not directly wind‐driven by linear dynamics; rather, the Kuroshio strengthens in years of abundant eddies of the Subtropical Counter Current, which is related to the current's instability state driven by the slow fluctuations of the large‐scale wind stress curl in the western Pacific. The seasonal transport fluctuation is also eddy‐forced, but has weaker amplitude because the seasonal time scale is of the same order as the eddy‐propagation time scale, and transport‐producing eddy signals tend to overlap east of Taiwan. Key Points Interannual Kuroshio variations Eddy‐driven dynamics Far‐reaching impacts on western Pacific