The launches, which come in the same week that Sharapova knocked Lindsay Davenport off the number one seed spot, feature an Estee Lauder color cosmetics line for Williams and a fragrance line that Sharapova is endorsing through Parlux.
Williams has been named as guest creator for Flirt, a color-driven make-up line by BeautyBank, part of the Estee Lauder group. The deal will see Williams promoting the brand for a year, with the first of her creations set to be rolled out in department stores in February.
Williams, who has previously promoted Avon cosmetics products with sister Venus, will appear as the face behind a significant media campaign to promote the line. She has also launched her own clothing and apparel lines in the course of the last two years.
Russian national Sharapova is taking part in a soft launch of the new Maria Sharapova perfume line this week, that will see it made first available in Macy's East stores across the New York City area.
Sharapova says that she has worked on the development of the perfume since its inception. Sports critics tipped her for stardom when she won her first major tournament at Wimbledon in 2004 aged 17. Her sporting ability combined with her good looks make her earnings potential enormous, both on and off the court.
Traditionally cosmetic and fragrance products have been endorsed by Hollywood and music stars, but with the increasing following behind women's tennis - evinced by the growing earnings of the top players - endorsement of sports, fashion and cosmetics products is becoming increasingly popular in women's tennis circles.
So far in 2005, both of the tennis stars have earned in excess of $1 million a piece from tennis playing alone - a figure that is thought to represent a fraction of their combined potential incomes from sponsorship deals.
Although the earnings still pale when compared those of top male seed Roger Federer - which so far this year have amounted to over $4 million - the figures represent a huge increase on previous years, reflecting the growing interest and following that the sport is now generating.