  We examine the sensitivity of electric dipole moments (EDMs) to new
$CP$-violating physics in a hidden (or dark) sector, neutral under the Standard
Model (SM) gauge groups, and coupled via renormalizable portals. In the absence
of weak sector interactions, we show that the electron EDM can be induced
purely through the gauge kinetic mixing portal, but requires five loops, and
four powers of the kinetic mixing parameter $\epsilon$. Allowing weak
interactions, and incorporating the Higgs and neutrino portals, we show that
the leading contributions to $d_e$ arise at two-loop order, with the main
source of $CP$-violating being in the interaction of dark Higgs and heavy
singlet neutrinos. In such models, EDMs can provide new sensitivity to portal
couplings that is complementary to direct probes at the intensity frontier or
high energy colliders.
