Quinn has received two Primetime Emmy Award nominations for his performances in the television films An Early Frost (1985) and Bury My Heart at Wounded Knee (2007).

His mother, Teresa, was a homemaker, but also worked as a bookkeeper and in the travel business, and his father, Michael Quinn, was a professor of English literature at Rock Valley College.

Quinn next starred in the controversial television film An Early Frost, about a young gay lawyer dying of AIDS (it was broadcast on NBC on November 11, 1985, and co-starred Gena Rowlands, Ben Gazzara and Sylvia Sidney).

Quinn played Kerry Max Cook in the 2005 movie The Exonerated, a true story about people on death row who had been freed.

In 2010, he played a cameo role as William Rainsferd in the French-made film Sarah's Key, set during World War II.

[19][20] As an avid sports fan, Quinn supports the Chicago Cubs, the Green Bay Packers, Michael Jordan, Rory McIlroy, and Roger Federer.

[22] Quinn has participated in charity golf events for the East Lake Foundation, a community redevelopment program,[23] and Samuel L. Jackson's "One for the Boys" campaign about testicular cancer awareness.

[24] In 2010, Quinn attended a premiere benefit screening of A Shine of Rainbows for the International Children's Media Center (ICMC) and The American Ireland Fund (AIF).

[25] In 1991, he read a segment from Franz Kafka's The Metamorphosis as part of MTV's "Books: Feed Your Head" literacy promotion PSAs.