Born in Manhattan, she attended the Professional Performing Arts School before having minor roles in the films Private Parts (1997), Annie (1999) and Blind Date (2007).

She is best known for playing Haley Dunphy in the ABC sitcom Modern Family (2009–2020), for which she received a nomination for the Critics' Choice Television Award for Best Supporting Actress in a Comedy Series.

[1] Hyland also had roles in the films Geek Charming (2011), Struck by Lightning (2012), Scary Movie 5 (2013), Vampire Academy (2014), See You in Valhalla (2015), XOXO (2016), Dirty Dancing (2017), and The Wedding Year (2019).

[11] From 2009 to 2020, Hyland played Haley Dunphy on the ABC sitcom Modern Family, for which she and the rest of the show's cast won the Screen Actors Guild Award for Outstanding Performance by an Ensemble in a Comedy Series each year from 2011 through 2014.

[20][21] Additional musical projects and theatre productions Hyland has performed in are: Kerrigan-Lowdermilk Live (2013 concert), Hair (2014 adaptation at the Hollywood Bowl), The Unauthorized Musical Parody of Scream (2014 play at Rockwell Table & Stage) and The Kindred Foundation for Adoption created by Jenna Ushkowitz and Samantha Futerman (2015 fundraiser).

[34][35] Hyland sang her debut performance of "Met At a Party" with Jordan McGraw (son of Dr. Phil) at the 2019 Teen Choice Awards.

[48][49][50] In August 2014, Hyland obtained a domestic violence temporary restraining order against Prokop[51] for physically and verbally abusing her throughout the four years of their relationship.

An outdoor bridal shower in early June 2022 marked the end of their two-year delay,[59] and the couple were married at a California vineyard on August 20, 2022.

[66] In a December 2018 Self magazine article, Hyland said she had contemplated suicide because she felt she was a burden on her family and blamed herself for her body rejecting her father's kidney.