She was featured on the cover of Playboy several times (initially credited as Barbi Klein) and in nude photo layouts in the March 1970, December 1973, January 1975, and December 1985 issues, although she was never one of the magazine's "Playmates of the Month".
Benton is known for her years as a regular on the country variety series Hee Haw, appearing in comic sketches with other cast members. She left the program after four seasons to concentrate on a more Hollywood-oriented career. She also starred in the short-lived 1977 ABC-TV comedy series Sugar Time!, about an aspiring female rock group.
Benton was also a recording artist with some success. Her record "Brass Buckles" (1975) was a top-five hit on Billboard's country singles chart. Benton has recorded eight albums, the last of which she personally produced in 1979. She also composed the songs, sang them, and played piano. One of her better-known songs was "Ain't That Just the Way" (1976) - a number one hit in Sweden for 5 weeks, which was also a major hit for Lutricia McNeal in 1996, and was recorded by the Dutch singer Patricia Paay under the title Poor Jeremy in 1977.
Benton was born Barbara Lynn Klein in New York City, New York, to a Jewish family. She moved with her parents to California when she was 2 years old. She grew up in Sacramento, California and attended Rio Americano High School. At the age of 16 she began to model to help supplement her income. Following high school she attended UCLA, and at age 18 took a job with Playboy to appear on their entertainment show Playboy After Dark. Her role was as co-host and beautiful companion to the show's director of entertainment, Hugh Hefner. After recording two sessions Hefner asked the young co-ed for a date. Upon being asked she reports demurring to the 42-year-old Mr. Hefner: "I don't know, I've never dated anyone over 24 before." To which Hefner replied, "That's all right, neither have I." The two began a relationship that lasted several years, and placed Benton in the center of the Playboy enterprise. Hefner convinced her to change her name from Barbara Klein to the more marketable Barbi Benton. She appeared on the cover of Playboy magazine four times: July 1969, March 1970, May 1972 and December 1985. Though she was featured in a number of photo-essays, she was never a Playmate of the Month. She landed a spot on television's Hee Haw doing short comic sketches, and subsequently enjoyed a career as a country singer. She also began acting, and appeared in a few "B" movies before appearing as a featured repeat performer on a number of popular television shows, including The Love Boat and Fantasy Island. Benton lived with Hefner from 1969 until 1976. Years later when the TV series The Girls Next Door visited her in Aspen, Colorado, she expressed gratitude that the two had remained friends.
Benton married George Gradow, a real-estate developer, on October 14, 1979. The couple have two children, Alexander (born August 23, 1986) and Ariana (born 1988). For many years, they divided their time between their homes in Aspen and Los Angeles.
On October 22, 2011, Josh Sigurdson asked Hugh Hefner over Twitter what his favorite memory of Playboy After Dark was. To that, Hefner replied: "My best memory from Playboy After Dark was meeting Barbi."