Upon graduation, Gould accepted a position at Randolph-Macon Woman's College in Lynchburg, Virginia, where he spent three years teaching and doing stage work.
He made his professional theatre debut in 1955 as Thomas Jefferson in The Common Glory in Williamsburg.

In 1956, Gould was offered a professorship in the drama department at the University of California, Riverside, which he accepted.
He taught there until 1960, when he decided to try professional acting himself.
He had difficulty finding acting jobs at first, and had to take work as a security guard and as a part-time acting teacher at UCLA.

Gould made his film debut in Two for the Seesaw but was not credited for his work; his first credited role was a small part in The Coach (both 1962).
In 1962 he appeared as Prosecutor Tom Finney on the TV western The Virginian in the episode titled "The Accomplice."
He gradually found more work and gained roles in The Yellow Canary, a Rod Serling movie with Pat Boone, Jack Klugman, and Barbara Eden; The Satan Bug; Inside Daisy Clover; and Harper, starring Paul Newman.

Gould worked steadily in television in the 1960s and early 1970s, including roles in Dennis the Menace, Dr. Kildare, Hazel, The Twilight Zone, The Donna Reed Show, Get Smart, Hogan's Heroes, I Dream Of Jeannie, The F.B.I., The Big Valley, Cannon and Mission: Impossible.
Gould originated the role of Marlo Thomas's father Lou in the 1965 pilot for That Girl, but the series role went to Lew Parker.
He appeared in The Long, Hot Summer  and He & She, two short-lived television series.
Gould also acted in a pilot, later broadcast as a 1972 episode of Love, American Style titled "Love and the Happy Days" as Howard Cunningham, the frustrated father of a young man named Richie Cunningham (played by Ron Howard).

When ABC turned that episode into a series called Happy Days, Gould was tabbed to reprise the Howard Cunningham role.
However, when production was delayed, he went abroad to perform in a play.
Midway through the play's run, after learning Happy Days was ready to begin shooting, he decided to honor his commitment to the stage production and passed on the part, which led to Tom Bosley being cast as the family patriarch.
Gould would later state that a requirement to shave his beard was also a factor in his declining the role.

Gould had worked in television and film for almost fifteen years before his career really took off with his portrayal of Kid Twist in The Sting (1973); he appeared in Woody Allen's Love and Death (1975); as the villainous head of a conglomerate in Silent Movie (1976, directed by Mel Brooks), and made guest appearances on television shows such as Hawaii Five-O (multiple appearances as Honore Vashon, one of the series' most memorable villains), Petrocelli, The Love Boat and Soap,  where he played the hospital roommate of Jody Dallas (Billy Crystal) who has suicidal feelings while deciding whether or not to undergo a sex change.

In 1972, Gould was cast as Martin Morgenstern, the father of Mary's best friend Rhoda, in an episode of The Mary Tyler Moore Show.
He reprised the role the following year and was hired as a regular when Rhoda became a spin-off in 1974.
Gould appeared in the short-lived 1977 series The Feather and Father Gang, starring as Harry Danton, a smooth-talking ex-con man, with Stefanie Powers as Toni "Feather" Danton, his daughter and a hard-working, successful lawyer.
The show was canceled after 13 episodes, and Gould   returned to Rhoda for the remainder of its run.

Gould also appeared in the miniseries Washington: Behind Closed Doors.
In the 1980 NBC miniseries The Scarlett O'Hara War, he portrayed Louis B. Mayer and gained an Emmy nomination.
He appeared as Chad Lowe's grandfather in Spencer, and played a Jewish widower wooing the Christian Katharine Hepburn in Mrs. Delafield Wants to Marry.
Other roles included a married man having an affair with another member of his Yiddish-speaking club in an episode of the PBS series The Sunset Years, and as the owner of a deli grooming two African-American men to inherit his business in Sing
Upon graduation, Gould accepted a position at Randolph-Macon Woman's College in Lynchburg, Virginia, where he spent three years teaching and doing stage work. He made his professional theatre debut in 1955 as Thomas Jefferson in The Common Glory in Williamsburg.
In 1956, Gould was offered a professorship in the drama department at the University of California, Riverside, which he accepted. He taught there until 1960, when he decided to try professional acting himself. He had difficulty finding acting jobs at first, and had to take work as a security guard and as a part-time acting teacher at UCLA.
Gould made his film debut in Two for the Seesaw but was not credited for his work; his first credited role was a small part in The Coach (both 1962). In 1962 he appeared as Prosecutor Tom Finney on the TV western The Virginian in the episode titled "The Accomplice." He gradually found more work and gained roles in The Yellow Canary, a Rod Serling movie with Pat Boone, Jack Klugman, and Barbara Eden; The Satan Bug; Inside Daisy Clover; and Harper, starring Paul Newman.
Gould worked steadily in television in the 1960s and early 1970s, including roles in Dennis the Menace, Dr. Kildare, Hazel, The Twilight Zone, The Donna Reed Show, Get Smart, Hogan's Heroes, I Dream Of Jeannie, The F.B.I., The Big Valley, Cannon and Mission: Impossible. Gould originated the role of Marlo Thomas's father Lou in the 1965 pilot for That Girl, but the series role went to Lew Parker. He appeared in The Long, Hot Summer  and He & She, two short-lived television series. Gould also acted in a pilot, later broadcast as a 1972 episode of Love, American Style titled "Love and the Happy Days" as Howard Cunningham, the frustrated father of a young man named Richie Cunningham (played by Ron Howard).
When ABC turned that episode into a series called Happy Days, Gould was tabbed to reprise the Howard Cunningham role. However, when production was delayed, he went abroad to perform in a play. Midway through the play's run, after learning Happy Days was ready to begin shooting, he decided to honor his commitment to the stage production and passed on the part, which led to Tom Bosley being cast as the family patriarch. Gould would later state that a requirement to shave his beard was also a factor in his declining the role.
Gould had worked in television and film for almost fifteen years before his career really took off with his portrayal of Kid Twist in The Sting (1973); he appeared in Woody Allen's Love and Death (1975); as the villainous head of a conglomerate in Silent Movie (1976, directed by Mel Brooks), and made guest appearances on television shows such as Hawaii Five-O (multiple appearances as Honore Vashon, one of the series' most memorable villains), Petrocelli, The Love Boat and Soap,  where he played the hospital roommate of Jody Dallas (Billy Crystal) who has suicidal feelings while deciding whether or not to undergo a sex change.
In 1972, Gould was cast as Martin Morgenstern, the father of Mary's best friend Rhoda, in an episode of The Mary Tyler Moore Show. He reprised the role the following year and was hired as a regular when Rhoda became a spin-off in 1974. Gould appeared in the short-lived 1977 series The Feather and Father Gang, starring as Harry Danton, a smooth-talking ex-con man, with Stefanie Powers as Toni "Feather" Danton, his daughter and a hard-working, successful lawyer. The show was canceled after 13 episodes, and Gould   returned to Rhoda for the remainder of its run.
Gould also appeared in the miniseries Washington: Behind Closed Doors. In the 1980 NBC miniseries The Scarlett O'Hara War, he portrayed Louis B. Mayer and gained an Emmy nomination. He appeared as Chad Lowe's grandfather in Spencer, and played a Jewish widower wooing the Christian Katharine Hepburn in Mrs. Delafield Wants to Marry. Other roles included a married man having an affair with another member of his Yiddish-speaking club in an episode of the PBS series The Sunset Years, and as the owner of a deli grooming two African-American men to inherit his business in Sing
Harold Gould