  The Cepheid AW Per is a component in a multiple system with a long period
orbit. The radial velocities of Griffin (2016) cover the 38 year orbit well. An
extensive program of interferometry with the CHARA array is reported here, from
which the long period orbit is determined. In addition, a {\it Hubble Space
Telescope} high resolution spectrum in the ultraviolet demonstrates that the
companion is itself a binary with nearly equal mass components. These data
combined with a distance from {\it Gaia} provide a mass of the Cepheid
(primary) of M$_1$ = 6.79 $\pm$ 0.85 $M_\odot$. The combined mass of the
secondary is M$_S$ = 8.79 $\pm$ 0.50 $M_\odot$. The accuracy of the mass will
be improved after the fourth Gaia data release expected in approximately two
years.
