  We investigate the temperature and magnetic field dependence of the Polyakov
loop and heavy quark entropy in a bottom-up Einstein-Maxwell-dilaton (EMD)
holographic model for the strongly coupled quark-gluon plasma (QGP) that
quantitatively matches lattice data for the $(2+1)$-flavor QCD equation of
state at finite magnetic field and physical quark masses. We compare the
holographic EMD model results for the Polyakov loop at zero and nonzero
magnetic fields and the heavy quark entropy at vanishing magnetic field with
the latest lattice data available for these observables and find good agreement
for temperatures $T\gtrsim 150$ MeV and magnetic fields $eB\lesssim 1$ GeV$^2$.
Predictions for the behavior of the heavy quark entropy at nonzero magnetic
fields are made that could be readily tested on the lattice.
