  We formulate a consistent model predicting, in the leading order
approximation, maximal atmospheric mixing angle, vanishing reactor angle and
tan {\theta}_12 = 1/{\phi} where {\phi} is the Golden Ratio. The model is based
on the flavour symmetry A5 \times Z5 \times Z3, spontaneously broken by a set
of flavon fields. By minimizing the scalar potential of the theory up to the
next-to-leading order in the symmetry breaking parameter, we demonstrate that
this mixing pattern is naturally achieved in a finite portion of the parameter
space, through the vacuum alignment of the flavon fields. The leading order
approximation is stable against higher-order corrections. We also compare our
construction to other models based on discrete symmetry groups.
