Although mesoscale eddies are active in the Bay of Bengal (BoB), periodic eddies — a type of eddy that occurs annually in fixed time frames with similar patterns and trajectories — have received little attention. This study reports an eddy dipole, which consists of a pair of periodic eddies, in the northwestern BoB, and examines its characteristics and interannual variability. The eddy dipole usually forms in March and occupies the northwestern BoB for three months, then propagates southwestward and dissipates in June. On the basis of altimeter data, the eddy dipoles during 1993–2020 are identified and tracked using the winding-angle method. The eddy dipole features show obvious interannual variability. In particular, the eddy dipole was exceptionally weak in 1999, 2000 and 2008, which is related to extreme La Niña events. During these years, a positive wind stress curl anomaly occupied most the BoB, which effectively weakened the negative wind stress curl and thus the eddy dipole.