  In the present work we have studied Natural Inflation in the framework of the
Randall-Sundrum II brane model (RS-II) in the light of the latest Planck
results. Adopting the Randall-Sundrum fine-tuning, the model is characterized
by 3 parameters in total, namely the 5-dimensional Planck mass $M_5$ and the
two mass scales of the inflaton potential $f$ and $\Lambda$. We show in the
$n_s-r$ plane the theoretical predictions of the model together with the
allowed contour plots, and we conclude that the model is viable. By using the
Planck results only it is possible to determine the two mass scales of the
inflaton potential in terms of $M_5$, which remains undetermined. However,
there are several good theoretical reasons to consider a higher-dimensional
Planck mass of the order of $10 TeV$, which is compatible with primordial
nucleosynthesis. If we insist on considering a $M_5$ of this order of magnitude
all parameters are known and a sub-Planckian excursion of the inflaton scalar
field is achieved.
