  Neutrino oscillation experiments provide a unique window in exploring several
new physics scenarios beyond the standard three flavour. One such scenario is
quantum decoherence in neutrino oscillation which tends to destroy the
interference pattern of neutrinos reaching the far detector from the source. In
this work, we study the decoherence in neutrino oscillation in the context of
the ESSnuSB experiment. We consider the energy-independent decoherence
parameter and derive the analytical expressions for P$_{\mu e}$ and P$_{\mu
\mu}$ probabilities in vacuum. We have computed the capability of ESSnuSB to
put bounds on the decoherence parameters namely, $\Gamma_{21}$ and
$\Gamma_{32}$ and found that the constraints on $\Gamma_{21}$ are competitive
compared to the DUNE bounds and better than the most stringent LBL ones from
MINOS/MINOS+. We have also investigated the impact of decoherence on the
ESSnuSB measurement of the Dirac CP phase $\delta_{\rm CP}$ and concluded that
it remains robust in the presence of new physics.
