  We demonstrate that the angle between star's rotation axis and the observer's
line-of-sight, usually called the inclination angle, can be reliably determined
for Be stars via H$\alpha$ emission-line profile fitting. We test our method on
a sample of 11 Be stars with available long-baseline interferometric data from
the Navy Precision Optical Interferometer~(NPOI). We fit the H$\alpha$ emission
line profile of each star to obtain a spectroscopic inclination angle $i_{\rm
H\alpha}$. We then obtain an independent inclination angle estimate, $i_{\rm
V^2}$, by fitting the observed interferometric visibilities with model
visibilities based on a purely geometric representation of the light
distribution on the sky. The sample differences, $\Delta i \equiv i_{\rm
H\alpha} - i_{\rm V^2}$, are normally distributed with a mean of zero and a
standard deviation of $6.7$ degrees, and the linear correlation coefficient
between $i_{\rm H\alpha}$ and $i_{\rm V^2}$ is $r=0.93$. As Be stars comprise
upwards of one fifth of all main-sequence B-type stars, this H$\alpha$ line
profile fitting technique has the potential to provide an efficient method for
detecting correlated stellar spin axes in young open clusters. Furthermore, if
the orientation of the Be star circumstellar disk on the plane of the sky can
be constrained by polarization measurements, it is possible to determine the
full 3D stellar rotation vector of each Be star.
