Happy Days is an American television sitcom that originally aired from 1974 to 1984 on ABC. The show presents an idealized vision of life in 1950s and early 1960s America.

The family consists of Howard Cunningham, a hardware store owner, his homemaker wife Marion and the couple's two children, Richie, an optimistic if somewhat naive teenager, and Joanie, Ritchie's sweet but feisty younger sister. The Cunninghams also had an older son named Chuck, a character who disappeared during the second season.

The earlier episodes revolve around Richie and his friends, Potsie Weber, Ralph Malph and local dropout Arthur "The Fonz" Fonzarelli, but as the series progressed, "Fonzie" proved to be a favourite with viewers and soon more story lines were written to reflect his growing popularity. Soon Fonzie befriended Richie and the Cunningham family. The focus would also occasionally shift to other additional characters, such as Fonzie's cousin Chachi, who became a love interest for Joanie Cunningham.

This long-running show spawned several other television series, including Laverne & Shirley, Mork & Mindy, and Joanie Loves Chachi, and is currently a musical touring the United States.

Despite some inconsistencies, it is generally indicated that the events of the series begin in 1955 and, after eleven seasons, end in 1965. Most episodes take place about 19 years before the year of their first air date. The second season episode "The Not Making of the President" revolves around the 1956 presidential election, while the sixth season episode "Christmas Time" ends with a photo dated Christmas 1960. In the 10th season episode "Babysitting", Fonzie watches the first heavyweight championship fight between Cassius Clay and Sonny Liston on television. This boxing match occurred on February 25, 1964. In the first part of the series finale "Passages", Joanie and Chachi are wearing T-shirts that say "The Kinks – Summer 1965 Tour".

Full character list

• Howard "Mr. C." Cunningham (Tom Bosley) Husband, father, business owner, lodge member, family man. Most often seen reading the daily newspaper in his easy chair.
• Marion "Mrs. C." Cunningham (Marion Ross) Wife, mother and homemaker. She was the only character whom Fonzie allowed to call him by his real first name, Arthur, which she always did affectionately.
• Richie Cunningham (Ron Howard) Son and high school student. The protagonist for the first six years of the series. The character was written out of the show, leaving to join the United States Army, although Howard did return to make guest appearances as Richie during the show's final season. (1974-1980)
• Joanie Cunningham (Erin Moran) Daughter and a typical curious (read "snoopy") pre-teen girl.
• Arthur "Fonzie" / "the Fonz" Fonzarelli (Henry Winkler) First written in as a minor character, but became a hugely popular breakout character and was made a series regular.
• Warren "Potsie" Weber (Anson Williams) Richie's closest friend, and a talented singer. Somewhat more carefree and "worldly" than Richie in early seasons, he gradually becomes slightly dimwitted and, in the later seasons, quite so.
• Ralph Malph (Donny Most) Richie's friend, and a self-styled comedian. Left with Richie to join the Army (1974-1980). Returned as a guest star in the final season.
• Charles "Chachi" Arcola (Scott Baio) Fonzie's younger cousin and later, Al Delvecchio's stepson. Dated and eventually married, Joanie Cunningham.
• Matsuo "Arnold" Takahashi (Pat Morita) First depicted owner of Arnold's Drive-In (1975-1976), he obtained the moniker when he purchased the restaurant and people addressed its new owner as "Arnold". He moonlighted as a martial arts instructor, teaching self-defense classes at the drive-in after hours. Returned after Al Molinaro departed (1982-1983).
• Al Delvecchio (Al Molinaro) Drive-in owner/cook (1976-1982). Married Chachi's mother, thereby becoming Fonzie's uncle.
• Jenny Piccalo (Cathy Silvers) Joanie's boy-crazy best friend (1980-1983). Mentioned often in early episodes, but never appeared in person until the 1980 season. Returned as a guest star in the series finale. Jenny's father appeared in one episode, played by Silvers' real-life father Phil Silvers.
• Lori Beth Allen Cunningham (Lynda Goodfriend) Richie's girlfriend and later his wife (1977-1982). Returned as a guest star in the final season.