The ages of stars can be derived quite independently from the expansion age of the Universe (obtained by integrating the Friedmann equation), and have long been used as a point of comparison and constraint on cosmology; for example, globular cluster age-dating, nucleocosmochronology, and white-dwarf cooling estimates for the Galactic disk. The reader is referred to earlier reviews on these topics by Renzini (1991), Schramm (1989). For the purposes of this review, I briefly consider only two types of age determinations: those based on Galactic globular clusters, and a new estimate of the age based on a measurement of radioactive thorium in a metal poor Galactic halo star.