  We report the discovery of a highly eccentric long-period Jovian planet
orbiting the hot-Jupiter host HD\,83443. By combining radial velocity data from
four instruments (AAT/UCLES, Keck/HIRES, HARPS, Minerva-Australis) spanning
more than two decades, we find evidence for a planet with
m~sin~$i=1.35^{+0.07}_{-0.06}$\,\mj, moving on an orbit with $a=8.0\pm$0.8\,au
and eccentricity $e=0.76\pm$0.05. We combine our radial velocity analysis with
\textit{Gaia} eDR3 /\textit{Hipparcos} proper motion anomalies and derive a
dynamical mass of $1.5^{+0.5}_{-0.2} M_{\rm Jup}$. We perform a detailed
dynamical simulation that reveals locations of stability within the system that
may harbor additional planets, including stable regions within the habitable
zone of the host star. HD\,83443 is a rare example of a system hosting a hot
Jupiter and an exterior planetary companion. The high eccentricity of
HD\,83443c suggests that a scattering event may have sent the hot Jupiter to
its close orbit while leaving the outer planet on a wide and eccentric path.
