There’s nothing quite like charting the ascent of a major new Hollywood player, and as the premier pictorial weekly of its era, LIFE magazine was uniquely positioned to feature more than a few famous faces early in their careers, well before they became bona fide stars.

Here, LIFE.com offers a gallery of some of moviedom’s most celebrated (and gorgeous) young talents, on the very brink of life-altering fame, from Jane Fonda and Sophie Loren to Audrey Hepburn, Kim Novak, Rita Moreno and other legends.