  We present interferometric observations of the sigma Orionis triple system
using the CHARA Array, NPOI, and VLTI. Using these measurements, we spatially
resolve the orbit of the close spectroscopic binary (Aa,Ab) for the first time
and present a revised orbit for the wide pair (A,B). Combining the visual
orbits with previously published radial velocity measurements and new radial
velocities measured at CTIO, we derive dynamical masses for the three massive
stars in the system of M_Aa = 16.99 +/- 0.20 Msun, M_Ab = 12.81 +/- 0.18 Msun,
and M_B = 11.5 +/- 1.2 Msun. The inner and outer orbits in the triple are not
coplanar, with a relative inclination of 120-127 deg. The orbital parallax
provides a precise distance of 387.5 +/- 1.3 pc to the system. This is a
significant improvement over previous estimates of the distance to the young
sigma Orionis cluster.
