Born in Santa Monica, California to English parents, Bardsley grew up in the Los Angeles suburb of Chino Hills and began playing football at five years old.

During her junior year, she broke her left leg during college recruitment time resulting in some programs reportedly being concerned about her recovery.

[5] Bardsley attended California State University, Fullerton as a graphic design major and played for the Titans women's soccer team.

Sky Blue finished the regular season in fourth place with a 7–8–5 record and advanced to the 2009 Women's Professional Soccer Playoffs where they defeated the Washington Freedom 2–1 and Saint Louis Athletica 1–0 during the semi-final.

[9] After a 1–0 win against Los Angeles Sol, the team clinched the league championship and were later invited to the White House to be honoured by President Barack Obama.

Sky Blue head coach Pauliina Miettinen reveled, "As a team, it gives you a huge confidence boost when you know that you will get such a high level of play by your goalkeeper.

[13] During a training session in July 2010, Bardsley injured her clavicle when she led the league with five shutouts and a .90 goals against average (GAA).

[14] During the 2011 WPS season, Bardsley competed in only three matches for Sky Blue largely due to her 2011 FIFA Women's World Cup commitments with the England national team.

[22] Her two-year City stint started successfully, playing a pivotal role in the club winning the 2014 Continental Cup.

"[25] During the 2017–18 and 2018–19 seasons, despite being first choice in the England national side, Bardsley lost her starting position for Manchester City to English teenager Ellie Roebuck.

At the start of the following season, it was announced that Bardsley would miss the 2019 Women's International Champions Cup due to a hamstring injury.

[28] Bardsley announced her retirement on 2 May 2022 after suffering a long-term injury that forced her to withdraw from Great Britain's squad during the delayed 2020 Tokyo Olympics.

[31][32] Despite being born in the United States, as a dual citizen, Bardsley decided to represent England due to family connections in Stockport.

[35] By the 2011 FIFA Women's World Cup in Germany, Bardsley had taken over the national team's first choice goalkeeping position from Rachel Brown.

[36] After England's 1–1 opening group match draw with Mexico, coach Powell reported that Bardsley was "devastated" following the concession of a long-range equaliser to Mónica Ocampo.