Considered one of Broadway's most prominent leading men since the 2000s, he is best known for his Tony Award-nominated performance as Bobby in the 2006 Broadway revival of Company and for his television role as New York Assistant District Attorney (ADA) Rafael Barba in Law & Order: Special Victims Unit, where he had a recurring role in Season 14 and was promoted to a series regular in Seasons 15 to 19.

He is widely regarded for his versatility on stage, having performed musicals by Andrew Lloyd Webber, Stephen Sondheim, Kander and Ebb, Boy George, the Sherman Brothers and in plays by Mamet, Pinter, William Shakespeare, Tom Stoppard, and more.

He learned during the episode that his Catalan great-great-grandparents founded Garcia de Pou Restaurant Supply Store in Madrid, still owned and operated by members of his family.

He also learned that another branch of his family came from the small town of Navata, Girona, Catalonia, Spain, where they can be traced back fourteen generations.

[4] Esparza first drew attention with his performance in the 2000 Broadway revival of The Rocky Horror Show, which won him the Theatre World Award.

In 2008, he played Charlie Fox in the revival of David Mamet's Speed-the-Plow co-starring Jeremy Piven and Elisabeth Moss on Broadway.

Esparza appeared in a limited-engagement revival of Tom Stoppard's Arcadia, which began previews at the Ethel Barrymore Theatre on February 25, 2011, and opened on March 17, 2011.

He was involved in the workshop in 2008, the out-of-town tryout at the Ahmanson Theatre (Los Angeles) in 2010, and the Broadway production in 2012,[7] for which he received a 2012 Drama Desk Award nomination for Outstanding Actor in a Musical.

[10] In 2009, Esparza starred in a production of William Shakespeare's Twelfth Night at the Delacorte Theater (New York) with Anne Hathaway, from June 25 through July 12.

staged concert production of Anyone Can Whistle from April 8 to 11, 2010, opposite Sutton Foster as Fay Apple and Donna Murphy as the Mayoress Cora Hoover Hooper.

From October to December 2018, Esparza played the title role in Classic Stage Company's Off-Broadway production of The Resistible Rise of Arturo Ui.

[25] He appeared in the 2016 film Custody, written and directed by James Lapine, as Luis Sanjaro an Administration for Children's Services agent.

[26] In 2012, Esparza became a recurring actor on the long-running NBC drama series Law & Order: Special Victims Unit as Manhattan Assistant District Attorney Rafael Barba, starting in the third episode of the show's 14th season, "Twenty-Five Acts".

[29][30] Although having left the series to return to the stage, Esparza has been back on the show, making a very brief cameo before the main title in the season 21 episode "Redemption in Her Corner".