  We report the detection of three large millimeter flaring events from the
nearby Sun-like, $\epsilon$ Eridani, found in archival ALMA 12m and ACA
observations at 1.33 mm taken from 2015 January 17-18 and 2016 October
24-November 23, respectively. This is the first time that flares have been
detected from a Sun-like star at millimeter wavelengths. The largest flare
among our data was detected in the ALMA observations on 2015 January 17 from
20:09:10.4-21:02:49.3 (UTC) with a peak flux density of 28 $\pm$ 7 mJy and a
duration of 9 sec. The peak brightness of the largest flare is $ 3.4 \pm 0.9
\times 10^{14}$ erg s$^{-1}$Hz$^{-1}$, a factor of $>50\times$ times brighter
than the star's quiescent luminosity and $>10\times$ brighter than solar flares
observed at comparable wavelengths. We find changes in the spectral index
(F$_\nu\propto\nu^\alpha$) at the flare peak, with $\alpha$ = 1.81 $\pm$ 1.94
and a lower limit on the fractional linear polarization $|Q/I| = $ 0.08 $\pm$
0.12. This positive spectral index is more similar to millimeter solar flares,
differing from M dwarf flares also detected at millimeter wavelengths that
exhibit steeply negative spectral indices.
