  We present a catalog of GALEX Near-UV (NUV) and Far-UV (FUV) photometry for
the Palomar/MSU and SDSS DR7 spectroscopic M dwarf catalogs. The catalog
contains NUV measurements matched to 577 spectroscopically confirmed M dwarfs
and FUV measurements matched to 150 spectroscopically confirmed M dwarfs. Using
these data, we find that NUV and FUV luminosities strongly correlate with
H{\alpha} emission, a typical indicator of magnetic activity in M dwarfs. We
also examine the fraction of M dwarfs with varying degrees of strong line
emission at NUV wavelengths. Our results indicate that the frequency of M dwarf
NUV emission peaks at intermediate spectral types, with at least ~30% of young
M4-M5 dwarfs having some level of activity. For mid-type M dwarfs, we show that
NUV emission decreases with distance from the Galactic plane, a proxy for
stellar age. Our complete matched source catalog is available online.
