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We present the r-band luminosity function for a sample of 18,678 galaxies, with average redshift z = 0.1, from the Las Campanas Redshift Survey (LCRS). The luminosity function may be fitted by a Schechter function with M^*^ = -20.29+/-0.02+5 log h, α = -0.70+/-0.05 and φ^*^ = 0.019+/-0.001 h^3^ Mpc^-3^, for absolute magnitudes -23.0 <= M - 5 log h <= -17.5 and h = H_0_/(100 km s^-1^ Mpc^-1^). Over the same absolute magnitude range, the mean galaxy density is 0.029 +/- 0.002 h^3^ Mpc^-3^ for a volume extending to cz = 60,000 km s^-1^. We compare our luminosity function to that from other redshift surveys; in particular, our luminosity function normalization is consistent with that of the Stromlo-APM survey and is therefore a factor of 2 below the normalization implied by the b_J_ ~ 20 bright galaxy counts. Our normalization thus indicates that much more evolution is needed to match the faint galaxy count data, compared to minimal evolution models that normalize at b_J_ ~ 20. Also, we show that our faint-end slope α = -0.7, though "shallower" than typical previous values α = - 1, results primarily from fitting the detailed shape of the LCRS luminosity function, rather than from any absence of intrinsically faint galaxies from our survey. Finally, we find that the faint end of the luminosity function is dominated by galaxies with emission lines. Using [O II] λ3727 equivalent width W<SUB>lambda</SUB>_ = 5 A as the dividing line, we find significant differences in the luminosity functions of emission and nonemission galaxies, particularly in their α values; emission galaxies have Schechter parameters M^*^ = -20.03 +/- 0.03 + 5 log h and α = -0.9 +/- 0.1, while non-emission galaxies are described by M^*^ = -20.22 +/- 0.02 + 5 log h and α = -0.3 +/- 0.1. The average [O II] λ3727 equivalent widths do not change significantly with redshift, consistent with a star formation rate that stays constant over the depths sampled by the LCRS. This result holds for galaxies of different luminosities and over the respective redshift ranges that these galaxies may be observed, in particular up to about z = 0.2 for galaxies brighter than M^*^.