Living in the Cleveland area, I've heard a lot about Lebron James having the goal of being the first billionaire athlete (which explains James' interest in hanging with homeboy Warren Buffett). However, according to Forbes, Tiger Woods is going to beat James to the punch:

Woods is on track to pass $1 billion in career earnings by 2010. Becoming a billionaire-that is, having a net worth above $1 billion-will take slightly longer, since a sizable chunk of Woods' prize and endorsement money is eaten up by taxes and management fees-we estimated 45%. We also credited Woods with annualized investment returns of 8%.

From 1996 (the year Woods turned pro) to the present, we based his earnings on estimates from Forbes' Celebrity 100 list. In 2007, we estimate Woods earned $115 million, $65 million more than runner-up David Beckham.

Based on those criteria, we project Tiger Woods should join our list of the world's billionaires in 2011.

According to the article, Woods will be the first billionaire to have hit that mark purely as an athlete (meaning other billionaires have been sporty, but not actually professional athletes).

(I originally saw this item at The Wealth Report.)