  We have used the Gemini Multi-object Spectrograph (GMOS) on the Gemini South
8m telescope in exceptional conditions (0.6" FWHM seeing) to observe the outer
stellar disk of the Sculptor group galaxy NGC 300 at two locations. At our
point source detection threshold of r' = 27.0 (3-sigma) mag, we trace the
stellar disk out to a radius of 24', or 2.2 R_25 where R_25 is the 25
mag/arcsec**2 isophotal radius. This corresponds to about 10 scale lengths in
this low-luminosity spiral (M_B = -18.6), or about 14.4 kpc at a cepheid
distance of 2.0 +/- 0.07 Mpc. The background galaxy counts are derived in the
outermost field, and these are within 10% of the mean survey counts from both
Hubble Deep Fields. The luminosity profile is well described by a nucleus plus
a simple exponential profile out to 10 optical scale lengths. We reach an
effective surface brightness of 30.5 mag/arcsec**2 (2-sigma) at 55%
completeness which doubles the known radial extent of the optical disk. These
levels are exceedingly faint in the sense that the equivalent surface
brightness in B or V is about 32 mag/arcsec**2. We find no evidence for
truncation of the stellar disk. Only star counts can be used to reliably trace
the disk to such faint levels, since surface photometry is ultimately limited
by nonstellar sources of radiation. In the Appendix, we derive the expected
surface brightness of one such source: dust scattering of starlight in the
outer disk.
