ADDIS ABABA, Ethiopia—At the Radisson Blu hotel here last year, a senior fashion executive met with several of his top Asian apparel suppliers. His plea: Open for business in Africa.

“Africa is a huge opportunity to demonstrate how the industry can work together,” said Colin Browne, managing director of product supply and Asian sourcing for VF Corp., which owns such brands as Lee, Wrangler and Timberland. He pointed out to the factory owners a key advantage in Africa: it’s one of the few places where it’s possible to go from fiber to factory in one place.

Africa is the final frontier in the global rag trade—the last untapped continent with cheap and plentiful labor. Ethiopia’s garment sector has no minimum wage, compared with Bangladesh, where workers earn at least $67 a month, according to the International Labor Organization. Garment workers in Ethiopia started at about $21 a month as of last year, the Ethiopian government said.

Most countries in Africa benefit from a free-trade agreement with the U.S., an arrangement that saves retailers money. And, unlike other emerging economies such as Vietnam and Cambodia, many African countries can grow their own cotton, which shortens production time.

Mr. Browne’s thinking marks a change of mind-set. For more than a decade, Asia has dominated clothing manufacturing, churning out cheap clothes on inexpensive labor that are shipped to malls world-wide.