He is a graduate of the University of Washington and moved to Hollywood, California, to pursue his career soon after his 1982 graduation. He is best recalled for his roles as Jeffrey Beaumont in the cult film Blue Velvet, and Paul Atreides in Dune, as well as his television series roles as Agent Dale Cooper in Twin Peaks, Trey MacDougal in Sex and The City and Orson Hodge in Desperate Housewives. He is known for playing lead characters in several of director David Lynch's films.
In the 1993 film version of Franz Kafka's The Trial, MacLachlan played the lead role of the persecuted Josef K. He also had a recurring role in the American television series Sex and the City, portraying Dr. Trey MacDougal, the one-time husband of Charlotte York (Kristin Davis). He portrayed the spirit of Cary Grant in Touch of Pink. Noteworthy to critics was his uncanny ability to capture the nuances of Grant's mannerisms, his resemblance to Grant had been previously noted in an episode of Twin Peaks. MacLachlan also lent his voice to nefarious media mogul Donald Love in the video game Grand Theft Auto III.
In 1995, MacLachlan starred in Paul Verhoeven's Showgirls. The movie was heavily panned by critics and it collected seven Golden Raspberry Awards (from a record thirteen nominations). MacLachlan himself was deeply embarrassed with his involvement and infamously walked out of the film's premiere, at which he was allegedly heard exclaiming, "I thought this was an art movie.". He has stated that he did not walk out of the premiere and that he "suffered through the whole two hours of it."
MacLachlan has appeared in several plays, including John Kolvenbach's On an Average Day with Woody Harrelson, on Broadway in The Caretaker with Patrick Stewart, as well as in Romeo and Juliet, and the Shakespearean history Henry V.
In recent years, MacLachlan continues to play dark and/or morally ambiguous characters. This included a guest role on Law & Order: Special Victims Unit, in which he played a father who shot and killed a sociopathic child who murdered his son. After starring in the short-lived In Justice, MacLachlan has become a regular on Desperate Housewives. His character, the mysterious dentist Orson Hodge, first appeared during the show's second season, with MacLachlan becoming a full-time cast member with the start of season three.
On July 7, 2007, MacLachlan was one of the presenters at the London leg of Live Earth.
MacLachlan appeared in the 2008 movie, The Sisterhood of the Traveling Pants 2.
In the past, MacLachlan had longterm relationships with fellow co-stars (Laura Dern, Lara Flynn Boyle, and Heather Graham) from various projects directed by David Lynch. He also had a 6-year relationship with former supermodel, Linda Evangelista.
Kyle's wife gave birth to a baby boy named Callum Lyon MacLachlan. He was born on July 25, in LA. The baby weighed in at 8 lbs. 6 oz.
Kyle has two younger brothers named Craig and Kent, both residing in the Pacific Northwest.