The Connecticut Open was a professional tennis tournament played on outdoor hard courts under various names and in various venues from 1948 until 2019.

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It was most recently a Women's Tennis Association (WTA) Premier Tournament on the WTA Tour, held annually at the Cullman-Heyman Tennis Center in New Haven, Connecticut, United States, just before the fourth and last Grand Slam tournament of the year, the US Open.^[1] From 2005 through 2010, the tournament was also part of the ATP World Tour 250 series of the ATP Tour.

In 2019, the tournament sanction was sold to APG, a sports and entertainment company, which transferred it to Zhengzhou, China.^[2]

The tournament was created in 1948 as the U.S. Women's Hardcourt Championships and first played in Sacramento, California, in the United States. Over the 20 years of its first run, the event was held in various locations in the western United States: San Francisco; Berkeley, California; Salt Lake City, Utah; Seattle, Washington; La Jolla, California; and Denver, Colorado. Among the winners of the event were Doris Hart, Darlene Hard, Nancy Richey, Rosemary Casals, Billie Jean King, and Jane Bartkowicz. The event was discontinued in 1969 after the beginning of the Open Era.^[3]

In 1988, the United States Tennis Association (USTA) reinstated the tournament. The first edition of the new U.S. Women's Hardcourt Championships was held that year in San Antonio, Texas, first as part of Tier IV of the WTA Tour, then as an upgraded Tier III event in 1990. The championships were sponsored by Post Cereals in 1990^[4] and by Acura from 1992 to 1994.^[4] Over the first years of its second run, the tournament was won by several past or future World No. 1s, including Steffi Graf, Monica Seles, and Martina Navratilova. The event was held in Stratton Mountain, Vermont, in 1993 and 1994, but conflicts with the 1996 Summer Olympics prevented the tournament from being held the following two years. In 1997, the event returned again, now within Tier II and first in Stone Mountain, Georgia, then settling in 1998 in New Haven, Connecticut, under the new sponsorship of Pilot Pen.^[3] In the first years of its run in New Haven, the renamed Pilot Pen International saw its competition dominated by Lindsay Davenport (four-time runner-up in New Haven, one previous time in Stone Mountain, and 2005 champion) and Venus Williams (four-time champion from 1999 to 2002).

New Haven was already host to a men's tournament, the Pilot Pen International. It was created in 1973 in Bretton Woods, New Hampshire, as the Volvo International, and moved to Connecticut in 1990, where it took Pilot Pen sponsorship in 1997. When the men's event was cancelled in 1999, the women's Pilot Pen tournament remained the only one of the region.

In 2005, the USTA purchased the men's tournament of Long Island, New York,^[5] and merged it with the women's Pilot Pen International to create Pilot Pen Tennis, the first large joint ATP–WTA tournament leading to the US Open.^[6] The tournament became the last event of the US Open Series and continued to attract top players, including champions Caroline Wozniacki, Svetlana Kuznetsova, James Blake, Justine Henin, and Nikolay Davydenko.

In 2011, after the men's competition moved to Winston-Salem, the newly women's-only event was renamed the New Haven Open at Yale.^[7] In 2014, it was renamed the Connecticut Open.^[8]

In 2019, the Connecticut Open ended due to a lack of funding. The tournament's sanction was sold and assigned to Zhengzhou, China, after the 2019 US Open.^[9] In 2021, the Tennis in the Land tournament in Cleveland took over its former spot on the WTA schedule.^[10]

On August 23, 2011, 1:51 PM local time^[11] a 5.8 magnitude earthquake in Virginia stopped play for two hours^[12] while the main stadium was checked for damage by the fire department.

• Volvo International