  We present the first WFPC2 V, I photometry for the Sculptor Group galaxy NGC
300 in four fields ranging from the centre to the outer edge. We have made the
first measurement of the star formation histories in two disk fields: the
oldest stars were born at similar epochs and formation activity increased but
at different mean rates. The main disk stellar population is predominantly old,
consisting of RGB and AGB stars, based on a synthetic colour magnitude diagram
analysis. Z is found to have been more metal poor than 0.006 (or 0.33Zsolar)
with no evidence for significant change in the mean Z value over time in both
disk fields. In the central region, we find a dearth of bright stars with
respect to the two disk fields that cannot be explained by observational
effects. Taken at face value, this finding would agree with the Davidge (1998)
report of suppressed star formation there during the past 1Gyr with respect to
his disk fields at larger radii; but the possibility of significant central
extinction affecting our finding remains. We have also determined the first
distance modulus estimate based on the tip of the red giant branch method: on
the Cepheid distance scale of Ferrarese et al. (2000) we find (m-M)o =
26.56+/-0.07 (+/-0.13) mag; and a similar value from the Cepheid-independent
empirical method by Lee et al. (1993), both in good agreement with the Cepheid
distance determined by Freedman et al. (2001). A discrepancy between this and
the theoretical calibration of the red giant branch tip magnitude method
remains. Finally, we report a newly detected young (up to about 10Myr) stellar
association of about average size (~140pc) in one of the disk fields.
