  With the advent of Belle II and the LHCb upgrade, the precision measurements
of various B-Physics observables are on cards. This holds significant potential
for delving into physics beyond the standard model of electroweak interactions.
These measurements can also serve as means to establish limits on phenomena
occurring at much finer length scales, such as quantum decoherence, which may
arise due to potential discreteness in space-time or non-trivial topological
effects. In this work, we set up the formalism to investigate the impact of
quantum decoherence on several potential observables in $B$ meson systems. The
approach employs the trace-preserving Kraus operator formalism, extending
unitary evolution to non-unitary dynamics while maintaining complete
positivity. In this formalism, the decoherence effects are parametrized in
terms of a single parameter. Through the analysis of purely leptonic,
semileptonic, and non-leptonic decays of $B$ mesons, we identify observables
that could, in principle, be influenced by decoherence. The theoretical
expressions are provided without neglecting the impact of decay width
difference ($\Delta \Gamma$) and $CP$ violation in mixing. Considering that
many of these observables can be measured with high precision using the
abundant data collected by LHCb and Belle II, our formalism can be applied to
establish constraints on the decoherence parameter through multiple decay
channels. This offers an alternative set-up for such studies, which, at
present, are predominantly conducted in the neutrino sector.
