The 1999 ANZ Tasmanian International singles was the singles event of the sixth edition of the ANZ Tasmanian International. Patty Schnyder was the defending champion but did not compete that year.
The 1999 Toray Pan Pacific Open singles was the singles event of the twenty-fourth edition of the Toray Pan Pacific Open Tennis Tournament, the first WTA Tier I tournament of the year. Lindsay Davenport was the defending champion but lost in the quarterfinals to Amanda Coetzer.
The 1999 Copa Colsanitas singles was the singles event of the second edition of the Copa Colsanitas; a WTA Tier IV tournament and the most prestigious women's tennis tournament held in Colombia and Hispanic America. Paola Suárez was the defending champion but lost in the semifinals to Christína Papadáki.
The 1999 Faber Grand Prix singles was the singles event of the seventh edition of the Faber Grand Prix; a WTA Tier II tournament held in Hanover, Germany. Patty Schnyder was the defending champion but lost in the second round to Elena Likhovtseva.
The 1999 Evert Cup doubles was the doubles event of the eleventh edition of the tennis tournament played at Indian Wells, California, United States. It was the second WTA Tier I tournament of the year, and part of the US Spring tennis season. Lindsay Davenport and Natasha Zvereva were the defending champions but lost in the quarterfinals to Serena Williams and Venus Williams.
The 1999 Lipton Championships women's singles was the women's singles event of the fifteenth edition of the tennis tournament played at Miami, United States. It is the third WTA Tier I tournament of the year, and part of the US Spring tennis season. Venus Williams was the defending champion, and she successfully defending her title by defeating her sister Serena in the final 6–1, 4–6, 6–4.
The 1999 Lipton Championships women's doubles was the women's doubles event of the fifteenth edition of the tennis tournament played at Miami, United States. It is the third WTA Tier I tournament of the year, and part of the US Spring tennis season. Martina Hingis and Jana Novotná were the defending champions and won in the final 0–6, 6–4, 7–6(7–1) against Mary Joe Fernández and Monica Seles.
The 1999 Family Circle Cup singles was the singles event of the twenty-seventh edition of the tennis tournament played at Hilton Head, United States. It is the third WTA Tier I tournament of the year, and part of the US Spring tennis season. Amanda Coetzer was the defending champion but lost in the third round to Henrieta Nagyová.
The 1999 Bausch & Lomb Championships singles was the singles event of the twentieth edition of the Bausch & Lomb Championships; a WTA Tier II tournament held in Amelia Island, Florida, United States, played on green clay. Mary Pierce was the defending champion but lost in the quarterfinals to Conchita Martínez.
The 1999 Betty Barclay Cup doubles was the doubles event of the fifteenth edition of the Betty Barclay Cup, a WTA Tier II tournament held in Hamburg, Germany and part of the European claycourt season. Barbara Schett and Patty Schnyder were the defending champions but only Schett competed that year with Ruxandra Dragomir. The pair lost in the first round to Irina Spîrlea and Caroline Vis.
The 1999 Direct Line International Championships singles was the singles event of the twenty-fifth edition of the Eastbourne International, a WTA Tier II tournament held in Eastbourne, England, United Kingdom and part of the European grass court season. Jana Novotná was the defending champion but retired earlier in the year.
The 1999 Direct Line International Championships doubles was the doubles event of the twenty-fifth edition of the Eastbourne International, a WTA Tier II tennis tournament held in Eastbourne, England and part of the European grass court season. Mariaan de Swardt and Jana Novotná were the defending doubles champions but each competed with different partners in 1999. De Swardt partnered Elena Tatarkova and reached the semifinals where they lost to Martina Hingis and Anna Kournikova. Novotná teamed with Natasha Zvereva and they retired in the final to Hingis and Kournikova after losing the first set 4–6.
Serena and Venus Williams defeated Chanda Rubin and Sandrine Testud in the final, 4–6, 6–1, 6–4 to win the women's doubles tennis title at the 1999 US Open. It was the second doubles major title for the Williams sisters, and their second step towards completing the career Golden Slam in doubles.
The 1999 Italian Open singles was the singles event of the fifty-fifth edition of the tennis tournament played at Rome, Italy, the most prestigious tennis tournament in Southern Europe. It was the fifth WTA Tier I tournament of the year, and part of the European claycourt season. Martina Hingis was the defending champion but lost in the semifinals to Venus Williams.
The 1999 Italian Open doubles was the doubles event of the fifty-fifth edition of the tennis tournament played at Rome, Italy, the most prestigious tennis tournament in Southern Europe. It was the fifth WTA Tier I tournament of the year, and part of the European claycourt season. Virginia Ruano Pascual and Paola Suárez were the defending champions, but lost to Martina Hingis and Anna Kournikova in the quarterfinals.
The 1999 WTA German Open singles was the singles event of the fifty-fifth edition of the tennis tournament played at Berlin, Germany, the most prestigious tennis tournament in Latin Europe. It was the sixth WTA Tier I tournament of the year, and part of the European claycourt season. Lindsay Davenport and Natasha Zvereva were the defending champions, but only Zvereva participated this year with Mary Pierce. They were eliminated in the first round by Brie Rippner and Tara Snyder.
The 1999 Swisscom Challenge singles was the singles event of the sixteenth edition of the Swisscom Challenge; a WTA Tier I tournament and the most prestigious tournament held in Switzerland. Lindsay Davenport was the two-time defending champion, but she did not compete this year.
Sandrine Testud was the defending champion, but was defeated by Martina Hingis in the semifinals.
Jana Novotná was the defending champion, but she retired from tennis earlier in the year.
Venus Williams 
Mary Pierce 
