  We investigate the magneto-optical properties of two-dimensional
nonsymmorphic Dirac semimetals in the presence of antiferromagnetic order.
Using the Kubo formula, we calculate the conductivity tensor of two-dimensional
CuMnAs, a prototype antiferromagnetic Dirac material, as a function of light
frequency. From the finite-frequency conductivity tensor, we derive the dynamic
dielectric function and magnetic linear dichroism, demonstrating how they are
influenced by the orientation of the N{\'e}el order parameter. Adjusting the
N{\'e}el vector changes both the sign and amplitude of the system's
magneto-optical response. We propose that magnetic linear dichroism
spectroscopy is a powerful technique for determining the orientation of the
N{\'e}el vector.
