Trivia

For the last two seasons of Mad Men (2007), he shaved the front of his head in order to make his character Pete Campbell look aged.

He got engaged to Alexis Bledel (March 20, 2013) and then married in June 2014.

In an April 2010 interview with The Guardian (UK) newspaper, Kartheiser revealed that after experiencing some of the material excesses of Hollywood (such as awards shows where already-wealthy people receive gift bags full of expensive free items), he started a process of shedding his possessions that includes selling or giving away most of what he owns. He told the interviewer that he now no longer owns a car (even though he lives in Los Angeles, a city that is notoriously difficult to get around in without one) and he moved into a very small one-room house that doesn't even have a toilet in it.

Failed the 9th grade.

Before he got married, he told The Guardian (UK) that he often wore a wedding ring in his private life so that he "can flash it to warn people off if [he] need[s] to," and that he has "never been monogamous" in any relationship.

Is the youngest out of 6 siblings.

Minneapolis, Minnesota: Starring in stage version of 'Pride and Prejudice' as the romantic lead, Mr. Darcy, at the Guthrie Theater in his hometown where he got is start as an actor (July 2013)

A deleted scene from Another Day in Paradise (1998) with Natasha Gregson Wagner, involving fellatio and rough sex, had to be cut from the movie in order to avoid an NC-17 rating. The scene is included in the uncensored director's cut on the flipside of the DVD.

He has German, Polish, Finnish, Swedish, and Luxembourgian ancestry. His matrilineal great-grandmother, Stella Louise Richter, immigrated from Blonie, Poland, with her parents, Stanley Richter and Anna Petrowski.

Has four sisters and one brother.

Born to Janet Marie Gruye and James Ralph Kartheiser, he has four sisters, Andrea, Colette, Elise, and Theresa and a brother, Nathan.

Good friends with Monica Keena.