Quigley was born in Joliet, Illinois on June 20, 1986. She has cited her father, who died when she was seven, as an inspiration for her playing basketball. She began following the WNBA when it debuted in 1997, and aspired to be a player in league. In high school, she played for Joliet Catholic Academy where she was named a WBCA All-American. She participated in the 2004 WBCA High School All-America Game.
Quigley was drafted by the Seattle Storm with the 22nd overall pick in the 2008 WNBA draft. She was cut by the Storm before the season started, and signed as a free agent with the Phoenix Mercury on May 11, 2008. She was a bench player for the Mercury, before being cut mid-season in 2009. Quigley played for the San Antonio Stars and Indiana Fever in the 2010 season, and signed with the Seattle Storm in the 2011 season. During all three stints, she came off the bench, never averaging more than 7 minutes per game. She was cut by the Storm after the 2011 season, and did not play in the WNBA in the 2012 season. She has said that she wondered if her career in the WNBA was over, and spent the 2012 summer as a basketball camp counselor in 2012.
Chicago Sky (2013–present)
In March 2013, Quigley was signed by the Chicago Sky, returning to the city where she had played in her college career. Pokey Chatman, then-coach and general manager of the Sky, wanted to sign Quigley after watching her play in European leagues. In the 2013 season, she continued to be a bench player, averaging 9.4 minutes per game. The 2014 season was a banner year for Quigley: she played a career-high 24.8 minutes per game, averaging 11.2 points. As a result, she was named the WNBA Sixth Woman of the Year. The Sky also had a successful year overall, appearing in their first WNBA Finals after defeating the Atlanta Dream and the Indiana Fever in the playoffs. However, they were swept by Phoenix Mercury in the Finals. Quigley averaged 25.7 minutes and 14.2 points per game in the playoffs. On February 23, 2015, Quigley re-signed a multi-year contract with the Sky. That season, Quigley was once again named WNBA Sixth Woman of the Year. The Sky achieved a 21–13 record, but were defeated by the Indiana Fever in the conference finals. In 2017, Quigley emerged as a starter for the Sky, and was named a WNBA All-Star for the first time in her career. She set career records with 32.3 minutes and 16.4 points per game. She was named an All-Star again in 2018, and won back-to-back Three-Point Contests in 2017 and 2018. Her score of 29 points in 2018 set an all-time record for the Three-Point Contest across both the NBA and the WNBA. In February 2019, she signed a one-year contract extension with the Sky for $117,500, making her the team's highest-paid player for the 2019 season. That season, she started all 34 games for the first time, averaging 13.8 points per game and making a league-high 80 three-pointers. She was also selected to the All-Star Game for the third consecutive year.
European leagues
In the 2008–09 season Quigley played for Turkey's Mersin in the TBBL League for the first time in her overseas career. In 2009–10 Quigley returned to Europe, this time she played for Pécs 2010 of Hungary. She became Hungarian champion and Hungarian Cup winner, and played in the EuroLeague Women as well. In the 2011–12 season Quigley was still the player of Pécs 2010, though the team could not participate in the Euroleague due to financial issues, thus the team competed in the Hungarian Championship only. The team finished in the third place in the national championship. Quigley averaged 16.68 points in the regular season and 17.50 in the play-offs. At the end of the season Quigley obtained Hungarian citizenship and debuted in the Hungarian national team against Slovakia. She participated in further preparation matches and eventually earned a place in the Hungarian roster for the EuroBasket Women 2013 qualification. On July 13, 2015, Fenerbahçe Istanbul announced her transfer to the club.