He also appeared in smaller roles on television series, such as So Notorious, The Slap, and 24, and on stage in Angels in America, The Glass Menagerie, and Smokefall.

[2][3] He was raised in the suburb of Green Tree, Pennsylvania, and attended Saints Simon and Jude Catholic School (closed 2010).

In 2006, Quinto played the role of Sasan, the haughty, bisexual Iranian-American best friend of Tori Spelling on her VH1 series So NoTORIous.

Murder is Dead, created by writer Victor Quinaz, closely followed by LUCID: A Matthew Dee Adventure written by writer/actor Michael McMillian.

He played a strangely lovable kidnapper in "Hostage: A Love Story", written by the comedy duo HoltandSteele, for Before the Door Pictures and Funny or Die.

[23] From October 2010 to February 2011, Quinto played the lead role of Louis Ironson in an Off-Broadway revival of Tony Kushner's Angels in America at the Signature Theatre, New York City.

[26] In 2013, Quinto played the role of Tom Wingfield in the American Repertory Theatre's production of The Glass Menagerie by Tennessee Williams.

Quinto played the role of Peter Sullivan in the film, in a cast that included Jeremy Irons, Kevin Spacey, Paul Bettany, Stanley Tucci, Penn Badgley and Demi Moore.

In October 2011, Quinto began a recurring role on the FX series American Horror Story as Chad, former owner of the house.

[31] In 2014, Quinto and his Before the Door partners produced a Chris Moore project, The Chair, a documentary series on Starz that shows the process of two directors bringing their first feature to the screen.

[35] In 2016, science fiction author John Scalzi released a novella, The Dispatcher, created specifically for Audible; Quinto narrated the story, as well as the second book in the series, Murder by Other Means.

[38] In 2022, Quinto made his debut on the West End stage in London as Gore Vidal in James Graham's new play Best of Enemies.

[43] He explained that, after the suicide of bisexual teenager Jamey Rodemeyer, he felt that "living a gay life without publicly acknowledging it is simply not enough to make any significant contribution to the immense work that lies ahead on the road to complete equality.

"[44] Prior to his coming out, Quinto had long been an active supporter of gay rights and organizations, including The Trevor Project.

[56] He called the manner of Spacey's announcement "deeply sad and troubling," feeling he had not stood up "as a point of pride—in the light of all his many awards and accomplishments—thus inspiring tens of thousands of struggling LGBTQ kids around the world", but instead as "a calculated manipulation to deflect attention from the very serious accusation that he attempted to molest one".