Diagnosed with Type 1 diabetes at age 12.
Has been nominated for Broadway's Tony Award four times: as Best Actor (Featured Role -Play) in 1978 for "Deathtrap;" as Best Actor (Musical) in 1982 for a revival of "Little Me" and in 1994 for a revival of "Damn Yankees!"; and as Best Actor (Play) in 1989 for "Lend Me a Tenor."
Has played both Jesus (in Godspell) and the Devil (in Damn Yankees) in major stage productions.
He has a brother and a sister. His mother was Hope Garber, who died in 2005; his father passed away in 1993.
He studied drama at HB Studio in Greenwich Village in New York City, and still lives in the neighborhood.
In 2008, he co-presented a gallery show for Canadian-born, LA and New York-based portrait painter Rainer Andreesen.
Is in a long-term romantic relationship with artist and ex-model Rainer Andreesen.
Jack Bristow, Garber's character on "Alias" (2001), was ranked #29 in TV Guide's list of the "50 Greatest TV Dads of All Time" [20 June 2004 issue].
License plate on his on-set bike at Disney is "SPYDAD."
Not only was he the one and only guest at "Alias" (2001) co-star Jennifer Garner and Ben Affleck's wedding, but he officiated at the ceremony after learning how to do so on the Internet.
Originated the role of Anthony in the 1979 Stephen Sondheim musical "Sweeney Todd, the Demon Barber of Fleet Street."
Originated the role of Clifford Anderson in the 1978 New York City production of "Deathtrap."
Originated the role of John Wilkes Booth in the 1990 Stephen Sondheim musical "Assassins".
Played the uncredited role as assistant bank manager in friend Ben Affleck's movie The Town (2010).
Received Tony Award nominations for "Deathtrap" (Featured Actor), "Little Me' (Actor - Musical), "Lend Me a Tenor" (Actor), and "Damn Yankees" (Actor - Musical).