  Decadal-long radial velocity surveys have recently started to discover
analogs to the most influential planet of our solar system, Jupiter. Detecting
and characterizing these worlds is expected to shape our understanding of our
uniqueness in the cosmos. Despite the great successes of recent transit
surveys, Jupiter analogs represent a terra incognita, owing to the strong
intrinsic bias of this method against long orbital periods. We here report on
the first validated transiting Jupiter analog, Kepler-167e (KOI-490.02),
discovered using Kepler archival photometry orbiting the K4-dwarf KIC-3239945.
With a radius of $(0.91\pm0.02)$ $R_{\mathrm{Jup}}$, a low orbital eccentricity
($0.06_{-0.04}^{+0.10}$) and an equilibrium temperature of $(131\pm3)$ K,
Kepler-167e bears many of the basic hallmarks of Jupiter. Kepler-167e is
accompanied by three Super-Earths on compact orbits, which we also validate,
leaving a large cavity of transiting worlds around the habitable-zone. With two
transits and continuous photometric coverage, we are able to uniquely and
precisely measure the orbital period of this post snow-line planet
($1071.2323\pm0.0006$ d), paving the way for follow-up of this $K=11.8$ mag
target.
