Born on Feb. 24, 1945, in San Mateo, CA, where he and his older brother Peter were raised, Bostwick was the son of a city planner father, Henry, and a homemaker mother, Betty. His father went on to become a modestly working actor, and his performer’s life rubbed off on his kids. By the time Bostwick was a student at San Mateo High School, he and his brother were putting on varying folk music and puppet shows for students. In the mid 1960s, Bostwick headed off to United States International University’s School of Performing Arts, but opted to transition from music to acting after an actress he was dating landed him in a play, “Take Her, She’s Mine,” at the Valley Music Theater. Upon graduating with an acting degree in 1967, he headed off to continue his graduate training at New York University, taking a year off to perform out west with the APA-Phoenix Repertory Company.
Back in New York, Bostwick had both his Off-Broadway and Broadway debuts in 1969, appearing in the rock musical “Salvation” and then moving on up to “Cock-a-Doodle Dandy.” In 1972, Bostwick nabbed a Tony nomination for originating the role of the charismatic Danny Zuko in the musical “Grease.” The highs of that year were somewhat tempered by a crushing low, as his young older brother Peter was killed in a car accident, but Bostwick put his energies into work, and after a series of small film roles, appeared opposite Susan Sarandon in the big screen adaptation of the musical classic, “The Rocky Horror Picture Show” (1975). As the film’s green young lover Brad Majors, Bostwick, along with his fiancé, Susan Sarandon, found himself stranded in the carnival-like world of transvestite, Dr. Frank-N-Furter (Tim Curry).
In 1976, Bostwick nabbed a second Tony nomination for a revival of “They Knew What They Wanted," but finally won the prestigious award in 1978, playing the lead in the country-themed musical “The Robber Bridegroom.” He found onscreen work to be better paying, however, and continued to juggle them both, including a dual role in the big feature satire “Movie Movie” (1978) and the CBS made-for-television movie, “Murder by Natural Causes” (1979), where an affair with a mentalist’s wife leads her to attempt spousal homicide. By 1980, Bostwick began what would become a four-year relationship with actress Lisa Hartman and gave a solid performance in the first of his TV miniseries based on Judith Krantz novels, including the good-looking, sometime photographer in “Scruples” (CBS, 1980). That year, he stepped back in time to play the real-life actor John Gilbert, reenacting Gilbert’s doomed romance with screen legend Greta Garbo in the NBC TV movie, “Moviola: The Silent Lovers” (1980).
Bostwick was back on the stage in 1981, based in Los Angeles and acting in the part of the Pirate King for the west coast premiere of “Pirates of Penzance,” but also got to put his musical skills to use as a steelworker in Studs Terkel’s PBS special, “Working” (1982), which celebrated the lives of working professionals. Bostwick’s aptitude, and stamina for miniseries work was visibly apparent by 1984, with the actor climbing aboard the mammoth multi-part CBS project “George Washington,” starring in the role of the titular general and first American President. Bostwick stayed in period mode with the syndicated World War II miniseries, “A Woman of Substance,” as the noble, but short-lived Major Paul McGill. In the fall of 1986, Bostwick would return to another early chapter of Washington’s life with “George Washington II: The Forging of a Nation,” which focused on Washington’s early political life and the birth of democracy.
Spending the last day of the 1986 in the Fiji islands, Bostwick married actress Stacey Nelkin, just over two years after the pair began dating. At the time, Bostwick was winding down on an ailing ABC sitcom “Dads” (1986-87), but had a miniseries “I’ll Take Manhattan” (1987) on the way – another project for CBS based on a Judith Krantz novel. Bostwick played Zachary Amberville, a dying magazine empire magnate before faring exceptionally well in another enormously epic World War II miniseries, the 12-part “War and Remembrance” (1988), for which his role of the heroic Lieutenant Carter “Lady” Aster netted him a Golden Globe Award as a Best Supporting Actor. Already steeped in WWII pieces, he then stepped into a third go-round with Judith Krantz for the CBS adaptation of her period drama, “’Til We Meet Again” (1989). The year 1989 also saw Bostwick making time for some kid friendly fare, playing the Wyatt family patriarch Jeffrey in both NBC’s "Parent Trap III” and "Parent Trap: Hawaiian Honeymoon."
In 1991, Bostwick made a return to Broadway for the much-heralded “Nick & Nora,” playing Dashiell Hammett’s famous sleuth Nick Charles – better known for all the MGM “The Thin Man” movies, starring William Powell and Myrna Loy during the 1930s. A lavish, expensive production, the musical closed after just nine performances, prompting Bostwick to step away from the tentative Broadway scene. His marriage to Nelkin ended that year, but the following year, he began dating actress Sherri Jensen, whom he later married in 1993. He was working steadily in television movies and features, guest-appearing on network series through the decade, expanding his family with a son, Brian, in 1995 and a daughter, Chelsea, in 1996. It was not until then, that he found a true network home with ABC’s “Spin City,” a series comeback of sorts for actor Michael J. Fox. As the deputy mayor of New York, the shorter Fox and the very tall Bostwick played off of one another with physicality and wordplay, with Bostwick going from surefooted American president to clueless Mayor Randall Winston.
“Spin City” lasted two seasons after the changeover from Fox to Charlie Sheen – following the former’s public admittance of his struggles with Parkinson's disease – with the six-season production’s home jumping from New York to Los Angeles. By then, Bostwick had made a permanent residence in Nyack, NY, outside of the city, to raise his family, putting in appearances on several network series and pilot attempts. From 2004 onward, he continued to recur as attorney Oliver Gates on "Law & Order: Special Victims Unit" (1999- ). He also returned to the world of feature films in a big way with a major role in 2007 – playing the unscrupulous attorney Dashiel Biedermeyer in the teen spy movie “Nancy Drew,” starring Julia Roberts’ niece, Emma Roberts.