  We report initial observations and analysis on the Type IIb SN~2016gkg in the
nearby galaxy NGC~613. SN~2016gkg exhibited a clear double-peaked light curve
during its early evolution, as evidenced by our intensive photometric follow-up
campaign. SN~2016gkg shows strong similarities with other Type IIb SNe, in
particular with respect to the \he~emission features observed in both the
optical and near infrared. SN~2016gkg evolved faster than the prototypical
Type~IIb SN~1993J, with a decline similar to that of SN~2011dh after the first
peak. The analysis of archival {\it Hubble Space Telescope} images indicate a
pre-explosion source at SN~2016gkg's position, suggesting a progenitor star
with a $\sim$mid F spectral type and initial mass $15-20$\msun, depending on
the distance modulus adopted for NGC~613. Modeling the temperature evolution
within $5\,\rm{days}$ of explosion, we obtain a progenitor radius of
$\sim\,48-124$\rsun, smaller than that obtained from the analysis of the
pre-explosion images ($240-320$\rsun).
