"Fred and Ethel Mertz, Little Ricky Ricardo, Lucy and Ricky

Ricardo" played by William Frawley, Vivian Vance, Keith

Thibodeaux, Lucille Ball and Desi Arnaz

Ethel, Lucy, Ricky and Fred

Vivian Vance (born Vivian Roberta Jones; July 26, 1909 – August 17, 1979) was an American actress best known for playing Ethel Mertz on the sitcom I Love Lucy (1951–1957), for which she won the Primetime Emmy Award for Outstanding Supporting Actress, among other accolades. She also starred alongside Lucille Ball in The Lucy Show from 1962 until she left the series at the end of its third season in 1965. In 1991, she received a star on the Hollywood Walk of Fame. She is most commonly identified as Lucille Ball’s longtime comedic foil from 1951 until her death in 1979.

Vance was born in Cherryvale, Kansas, the second of six children of Robert Andrew, Sr., and Euphemia Mae (Ragan) Jones. When she was six, her family moved to Independence, Kansas, where she eventually began her dramatic studies at Independence High School with instructor Anna Ingleman. Her love of acting clashed with her mother's strict religious beliefs. "Viv" soon rebelled, often sneaking out of her bedroom and staying out after curfew. She changed her surname to Vance and moved to Albuquerque, New Mexico, to find acting work, performing in the first show at the Albuquerque Little Theatre in 1930. She appeared there in many other plays, including This Thing Called Love and The Cradle Song. The local theatre community helped pay her way to New York City to study under Eva Le Gallienne.

When Desi Arnaz and Lucille Ball were casting their new television sitcom I Love Lucy in 1951, director Marc Daniels, who had previously worked with Vance in a theater production, suggested her for the role of landlady Ethel Mertz. Lucille Ball had wanted either Bea Benaderet or Barbara Pepper, both close friends, to play the role. CBS refused Pepper on the grounds that she had a drinking problem, and Benaderet was already playing Blanche Morton on The George Burns and Gracie Allen Show.

Ultimately, the 42-year-old Vance won the role on the new television program, which debuted October 15, 1951, on CBS. Vance's Ethel Mertz character was the landlady of a New York City apartment that she and her husband Fred owned on East 68th Street. The role of Fred Mertz was played by William Frawley, who was actually 22 years her senior. Despite their exceptional chemistry, comedic timing, and musical prowess together onscreen, Vance and Frawley did not get along offscreen. According to some reports, things first went sour when Frawley overheard Vance complaining about his age, stating that he should be playing her father instead of her husband. She used to skim through the before she memorized her lines to see how many scenes she had with "that stubborn-headed little Irishman." Others recall that they practically loathed each other on sight and that Vance was put-off by Frawley's cantankerous attitude.

Honored for her work in 1953, Vance became the first actress to win an Emmy Award for Outstanding Supporting Actress; she accepted her award at the Emmy ceremony in February 1954. She was nominated an additional three times (for 1954, 1956, and 1957) before the series ended.

In 1957, after the highly successful half-hour I Love Lucy episodes had ended, Vance continued playing Ethel Mertz on a series of hour-long specials titled The Lucille Ball-Desi Arnaz Show (later retitled The Lucy-Desi Comedy Hour). When I Love Lucy was reformatted into the hour-long Lucy-Desi shows in 1957, Desi Arnaz offered Vance and Frawley the opportunity to star in their own "Fred and Ethel" spin-off show. Although Frawley was very interested, Vance declined, mainly because she did not want to work on a one-on-one basis with Frawley, as they already had an acrimonious relationship. Also, she felt the Mertz characters would be unsuccessful in a show without the Ricardos. Vance's choice to decline the would-be show intensified the animosity between Frawley and her. Instead, Vance was interested in doing a series based on the life of Babs Hooten, a New York socialite who moves to New Mexico to run a hotel and ranch. Desi Arnaz financed a pilot starring Vance as Hooten titled Guestward, Ho!, which was shot in 1958 by Desilu; however, the show was rejected by CBS and Vance continued playing Ethel Mertz. Arnaz later retooled the show with model and actress Joanne Dru taking the lead role, selling the series to ABC, where it was subsequently cancelled after one season.

Vance died at age 70 on August 17, 1979 of metastatic breast cancer. After her death, Desi Arnaz said, "It’s bad enough to lose one of the great artists we had the honor and the pleasure to work with, but it’s even harder to reconcile the loss of one of your best friends."

Family members donated Vance's Emmy Award to the Albuquerque Little Theatre after her death. In a 1986 interview, Lucille Ball talked about watching I Love Lucy reruns and her feelings about Vance's performance:

"I find that now I usually spend my time looking at Viv. Viv was sensational. And back then, there were things I had to do—I was in the projection room for some reason—and I just couldn't concentrate on it. But now I can. And I enjoy every move that Viv made. She was something."

For her achievements in the field of television, Vance was posthumously awarded a star on the Hollywood Walk of Fame February 14, 1991, at 7000 Hollywood Boulevard.

Vance is memorialized in the Lucille Ball–Desi Arnaz Center in Jamestown, New York. On January 20, 2010, the San Francisco Chronicle reported that a local antique dealer had inherited many of Vance's photos and sc.r.a.p.books and a manu.s.c.rip.t  of her unpublished autobiography when John Dodds died in 1986.  Vance and Frawley were inducted into the Television Academy Hall of Fame in March 2012.

The story of how Vance was hired to play Ethel Mertz is told in I Love Lucy: A Funny Thing Happened on the Way to the Sitcom, a stage comedy that premiered in Los Angeles on July 12, 2018. Written by Gregg Oppenheimer (son of I Love Lucy creator-producer-head writer Jess Oppenheimer), it was recorded before a live audience for nationwide public radio broadcast, and later, online distribution.