21 Richest Billionaires In The World

13. Christy Walton

Facebook CEO Mark Zuckerberg talks about the new Facebook email service at an announcement in San Francisco, Monday, Nov. 15, 2010. AP Photo/Paul Sakuma)
MORRY GASH/AP

Rating: $41.2 Billion

The widow of John Walton is also the richest of the family, having inherited her husband's wealth in 2005, which was supplemented thanks to investment in solar panel company First Solar.

Contributor
Contributor

WhatCulture's former COO, veteran writer and editor.