H-alpha photometry of the brightest H II regions in 95 nearby spiral and irregular galaxies has been analyzed in order to study the dependence of the H II region populations on the properties of their parent galaxies. It is found that the brightest H II regions in Magellanic irregular galaxies are about 50 times brighter than those in early-type spirals of the same absolute magnitude. It is suggested that this difference is due to both an increase in the numbers of H II regions in late-type galaxies and a physical change in the characteristic sizes of the star-forming regions. 62 references.