  A significant percentage of OB stars are runaways, so we should expect a
similar percentage of their evolved descendants to also be runaways. However,
recognizing such stars presents its own set of challenges, as these older, more
evolved stars will have drifted further from their birthplace, and thus their
velocities might not be obviously peculiar. Several Galactic red supergiants
(RSGs) have been described as likely runaways, based upon the existence of bow
shocks, including Betelgeuse. Here we announce the discovery of a runaway RSG
in M31, based upon a 300 km s$^{-1}$ discrepancy with M31's kinematics. The
star is found about 21' (4.6 kpc) from the plane of the disk, but this
separation is consistent with its velocity and likely age ($\sim$10 Myr). The
star, J004330.06+405258.4, is an M2 I, with $M_V=-5.7$, $\log L/L_\odot$=4.76,
an effective temperature of 3700 K, and an inferred mass of 12-15$M_\odot$. The
star may be a high-mass analog of the hypervelocity stars, given that its
peculiar space velocity is probably 400-450 km s$^{-1}$, comparable to the
escape speed from M31's disk.
