Brett attended the University of Illinois at Urbana–Champaign, where he received a Bachelor of Fine Arts degree in Theater. Moving to Chicago in 1975, he began his career as an actor, appearing in several Chicago theater productions including the Stephen Schwartz musical, Godspell and Michael Weller's Moonchildren, for which he won Jeff Awards for his acting and production of the play. In 1978, Brett co-founded Chicago's famed Apollo Theater, where he produced over forty-five plays and musicals, including such award-winning productionsvague as the Steppenwolf Theater Company's production of True West, starring John Malkovich and Gary Sinese; Balm in Gilead, featuring Laurie Metcalfe; And a Nightingale Sang, with Joan Allen; Appearing Nightly, with Lily Tomlin; and David Mamet's Sexual Perversity in Chicago, with James Belushi. Brett has produced several plays for the New York stage, including Harry Chapin: Lies and Legends, with Amanda McBroom; and Banjo Dancing, with Stephen Wade.
In 1986, Brett co-produced the romantic comedy About Last Night..., for Columbia/TriStar Pictures. The film, directed by Edward Zwick, holds an 82% rating at Rotten Tomatoes and grossed $38.7 million domestically. As a screenwriter, Brett's first original screenplay, The Street Where You Live was a finalist for the Sundance screenwriting program. He went on to write more than a dozen original screenplays, including The Silent Service and Bomb Squad (Columbia/TriStar Pictures); Wildcard (Warner Brothers); Route 66 (Universal Pictures); and The Executive (Trimark Pictures).
From 1989-2000, Brett also wrote and or produced more than three dozen series for all of the major television networks.[example needed]
In 2000, Brett founded ByteSize Entertainment, a provider of short-form comedy content on the Internet. ByteSize delivered one minute clips of popular comedy shows, TV promos and film trailers to a subscriber base.[vague] The company was acquired in 2001 by Mind Arrow Systems.
In 2002, Brett partnered with Chicago's improvisational comedy theater, The Second City, to develop and produce comedy film and television projects. As head of The Second City Film & Television, Brett oversaw the company's numerous production deals with Sony Pictures Television, Comedy Central, Canada's CBC and Global Television Network. Also during this time, the company released its television series SCTV on DVD.
Following his tenure with The Second City Film & Television, Brett was recruited to be Head of Comedy for Network Live, a partnership of AOL, XM Satellite Radio and AEG. For Network Live, he produced and recorded over twenty-five hours of stand-up and sketch comedy, featuring such then-emerging talents as Zach Galifianakis, David Cross and The Upright Citizens Brigade.
In 2010, Brett founded Big Things, Inc., a digital media company focused on developing on-line brands and live events around passionate, niche communities. In 2011, Big Things launched MashPlant.com, the first website developed exclusively for middle school kids who wish to share their video, music, animation, writing, comedy and performance projects. MashPlant.com connects kids with experienced industry professionals, who help to provide insight and inspiration.
Brett was first married in 1993 to Donna Gibbons, a model, mime, and actress. They had two daughters, Jessie Jason (born 1989) and Julian Rose (born 1991). The family moved from Los Angeles to Glenview, IL in 1994, where Donna suddenly died shortly after. Brett now lives in Chicago's Lincoln Park with his wife, women's health expert, author and media personality, Dr. Lauren Streicher.