  We consider the 750 GeV diphoton resonance at the 13 TeV LHC in the ${\cal
F}$-$SU(5)$ model with a Standard Model (SM) singlet field which couples to
TeV-scale vector-like particles, dubbed $flippons$. This singlet field assumes
the role of the 750 GeV resonance, with production via gluon fusion and
subsequent decay to a diphoton via the vector-like particle loops. We present a
numerical analysis showing that the observed 8 TeV and 13 TeV diphoton
production cross-sections can be generated in the model space with realistic
electric charges and Yukawa couplings for light vector-like masses. We further
discuss the experimental viability of light vector-like masses in a General
No-Scale ${\cal F}$-$SU(5)$ model, offering a few benchmark scenarios in this
consistent GUT that can satisfy all experimental constraints imposed by the LHC
and other essential experiments.
