Singaporean Olivia Lum, age 45, debuts at number 39 as the list's youngest, and only female, member.

FORBES: Southeast Asia's 40 Richest

Olivia Lum, ranked 35 on the list, was born in poverty in Malaysia, and narrowly escaped a future as a child labourer.

FORBES: Asian Women At The Top Of World Business

When Olivia Lum had just started her water treatment firm, Hyflux, in Singapore, she could not afford a professional welder to build her first projects.

FORBES: Water Queen