  We present the discovery of VHS J183135.58$-$551355.9 (hereafter VHS
J1831$-$5513), an L/T transition dwarf identified as a result of its unusually
red near-infrared colors ($J-K_{\rm S}=3.633\pm0.277$ mag; $J-W2=6.249\pm0.245$
mag) from the VISTA Hemisphere Survey and CatWISE2020 surveys. We obtain low
resolution near-infrared spectroscopy of VHS J1831$-$5513 using Magellan/FIRE
to confirm its extremely red nature and assess features sensitive to surface
gravity (i.e., youth). Its near-infrared spectrum shows multiple CH$_{\rm 4}$
absorption features, indicating an exceptionally low effective temperature for
its spectral type. Based on proper motion measurements from CatWISE2020 and a
photometric distance derived from its $K_{\rm S}$-band magnitude, we find that
VHS J1831$-$5513 is a likely ($\sim$85$\%$ probability) kinematic member of the
$\beta$ Pictoris moving group. Future radial velocity and trigonometric
parallax measurements will clarify such membership. Follow-up mid-infrared or
higher resolution near-infrared spectroscopy of this object will allow for
further investigation as to the cause(s) of its redness, such as youth, clouds,
and viewing geometry.
