  We present a novel mechanism of electroweak baryogenesis where \textit{CP}
violation occurs in a dark sector, comprised of standard model gauge singlets,
thereby evading the strong electric dipole moment constraints. In this
framework, the background of time-like component of a new gauge boson
$Z^\prime_\mu$, generated at electroweak temperatures, drives the electroweak
sphaleron processes to create the required baryon asymmetry. We first discuss
the crucial ingredients for this mechanism to work, and then show that all of
them can be elegantly embedded in ultraviolet completions with spontaneously
broken gauged lepton number. The models under consideration have a rich
phenomenology and can be experimentally probed in leptophilic $Z^\prime$
searches, dark matter searches, heavy Majorana neutrino searches, as well as
through hunting for new Higgs portal scalars in multi-lepton channels at
colliders.
