  We investigate the response of Casimir energies to fluctuations in a scalar
field in a weak gravitational field in the $\kappa$-deformed space-time. We
model the Casimir plates in a gravitational field by $\kappa$-deformed Rindler
coordinates and calculate the Casimir energy using the $\kappa$-deformed scalar
field. We show that the Casimir energy accelerates in a weak gravitational
field like a mass. Thus, our calculations show that the mass-energy equivalence
principle holds in $\kappa$-deformed space-time even though a length scale is
introduced through space-time non-commutativity.
