Maria Sharapova retired from tennis by 2000.
The list of WTA number 1 ranked players shows the professional women 's tennis players who have been or currently are ranked world No. 1 by the Women 's Tennis Association , along with the dates of first reaching and losing that spot . Maria Sharapova . She won the year-ending WTA Finals in her debut in 2004 . The WTA Finals ( formerly known as the WTA Tour Championships short : WTA Championships ) , is a professional tennis tournament played annually at the end of the season for the top-ranked players on the Women 's Tennis Association ( WTA ) tour . The Women 's Tennis Association ( WTA ) , founded in 1973 by Billie Jean King , is the principal organizing body of women 's professional tennis .