M. Hamuy, et al. have compiled their observations of secondary and tertiary spectrophotometric standard stars for the southern hemisphere in the wavelength range 3300-7550 Angstroms. The observations were made using the RC spectrographs and CCD cameras on the 1.5m and 4m telescopes at CTIO. The machine-readable files contain monochromatic magnitudes vs. wavelength for 29 stars in ASCII and 31 stars in FITS format. Introduction: The author's observations of secondary and tertiary southern spectrophotometric standard stars have been used to generate computer-readable files containing monochromatic magnitudes vs. wavelength for the range 3300-7550 Angstroms. The authors modified the monochromatic fluxes of the secondary standards according to the calibration of Vega published in 1985 by D. S. Hayes, and adjusted the zero point of their energy distributions by matching their V(synthetic) magnitudes to the observed magnitudes. They have used these adjusted secondary standards to calculate new fluxes for the tertiary standards of Stone and Baldwin (1983MNRAS.204..347S). The spectrophotometric data are reported in the "sp" subdirectory, which consist of 29 files of blue magnitudes vs. wavelength and 30 files of red magnitudes vs. wavelength for different standard stars; 30 additional files contain magnitude vs. wavelength for the entire wavelength range. There are an additional two stars, HR 1903 and HR 2421, for which the data is only in FITS format. Information on the contents of the FITS files is contained in the FITS headers of those files.