The WTA Tier I tournaments were

Women's Tennis Association The Women's Tennis Association (WTA) is the principal organizing body of women's professional tennis. It governs the WTA Tour which is the worldwide professional tennis tour for women and was founded to create a better future for women's tenn ...

tennis Tennis is a racket sport that is played either individually against a single opponent ( singles) or between two teams of two players each ( doubles). Each player uses a tennis racket that is strung with cord to strike a hollow rubber ball c ...

elite tournaments held from 1990 until the end of the 2008 season. From 1988 to 1990, the different levels of WTA tournaments were referred to by the term 'Category', and there were 5 categories. Two of the Tier I tournaments, Indian Wells and

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, were also joint events held simultaneously with the

ATP Tour The ATP Tour is a worldwide top-tier tennis tour for men organized by the Association of Tennis Professionals. The second-tier tour is the ATP Challenger Tour and the third-tier is the ITF Men's World Tennis Tour. The equivalent women's organisa ...

Masters Series. There were initially 6 Tier I tournaments held annually from 1990. The list expanded to 8 events in 1993, 9 in 1997 and 10 in 2004, before being scaled back to 9 for 2008. In

2009 File:2009 Events Collage V2.png, From top left, clockwise: The vertical stabilizer of Air France Flight 447 is pulled out from the Atlantic Ocean; Barack Obama becomes the first African American to become President of the United States; 2009 Iran ...

the WTA changed the tournament categories, so that the majority of Tier I and Tier II tournaments were in one category, Premier Tournaments, split into three categories.

Events

Singles results

1990

1991

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

2004

2005

2006

2007

2008

Singles champions

Per year

Per player

* ''DOH = Doha, IND = Indian Wells, MIA = Miami, CHA = Charleston, BER = Berlin, ROM = Rome, CAN = Canada, TOK = Tokyo, MOS = Moscow, SAN = San Diego, ZUR = Zürich, CHI = Chicago, BOC