The show follows the life of nerdy Everyman Eric Forman and his five teenaged friends: Donna Pinciotti, the feminist next-door neighbor and Eric's girlfriend; Steven Hyde, a cynical, hard-rocking stoner and Eric's childhood friend; Michael Kelso, a dim-witted, narcissistic ladies man; Jackie Burkhart, a self-involved high school cheerleader overly preoccupied with wealth and status; and Fez, a sometimes goofy foreigner, whose country of origin is ambiguous, whose real name is unknown to all but him, and whose hormones are, at times, out of control. Eric drives a 1969 Vista Cruiser, a station wagon given to him by his father in the first episode.
Other main characters include Red Forman, Eric's overbearing war veteran father, obsessed with making "...him a man, which he's not" and using the word "dumb-ass" frequently plus always threatening people with putting his 'foot in your ass'; Eric's overprotective mother, Kitty, who is caught up in trying to be a full-time mom and housewife, while maintaining a job as a nurse in a local hospital; and Laurie Forman, the promiscuous older sister who can do no wrong in the eyes of her father. The show also follows the relationship of Bob Pinciotti and Midge Pinciotti, Donna's parents, both of whom are slow witted and easily influenced by the movements and fads of the '70s, which sometimes places stress on their marriage. Tommy Chong also appears as the recurring character of Leo, the stoner owner of the Foto Hut.
- Topher Grace as Eric Forman (seasons 1–7; uncredited special guest season 8)
- Mila Kunis as Jackie Burkhart
- Ashton Kutcher as Michael Kelso (seasons 1–7; special guest season 8)
- Danny Masterson as Steven Hyde
- Laura Prepon as Donna Pinciotti
- Wilmer Valderrama as Fez
- Debra Jo Rupp as Kitty Forman
- Kurtwood Smith as Red Forman
- Tanya Roberts as Midge Pinciotti (seasons 1–3; special guest seasons 6–7)
- Don Stark as Bob Pinciotti
- Lisa Robin Kelly (seasons 2–3; recurring season 1; special appearance season 5) and
- Tommy Chong as Leo (seasons 4 & 8; special guest seasons 2–3 & 7)
- Josh Meyers as Randy Pearson (season 8)
Although the show has been on for over seven years, the timeline has been noticeably slowed. When the show first began in 1998, the show was set in May 1976, and in the past seven seasons, only three years have gone by. The series was set in 1977 from the middle of its first season to the end of the third, and then in 1978 until the sixth season. Hyde had an 18th birthday in 1978, despite dialogue that suggests that he is older than Eric, who turned 17 in the second episode (which was in 1976). Eric also turned 18 in 1978, two years after turning 17. This, combined with the fact that new holiday-themed episodes run every year, means the sense of time on That '70s Show is loose at best. Currently, the show is vaguely set in "1979."
Several changes were made to the Red Forman and Leo characters in the 8th season. It is revealed that Leo, the aging hippie, whose full first name is Leonard, was a supply truck driver in WWII, who was decorated with a medal that "looked like a purple heart." Red, a fellow veteran (of both WWII and the Korean War) who in the past couldn't stand Leo, gains newfound respect for him. Collectively, they still have no respect for Bob's service in the National Guard.
Eric Forman was written out the series following the seventh season finale, as the actor opted to pursue interests outside That '70s Show. Michael Kelso was written out in the fourth episode of season eight for the same reason. A new character by the name of Randy Pearson was introduced to take up the slack, which he unfortunately didn't do.
The show has gained recognition for providing a bold retrospective to a decade full of political events and technological milestones that have dramatically shaped the world today. The show cleverly tackles the significant social phenomena of 1970s America: feminism, new attitudes towards sexuality, the economic hardships of recession, developing mistrust in the American government among blue collar workers, teenage recreational drug use, and developments in entertainment technology, from the TV remote (or "the clicker"), to Pong.
The show usually opens with the theme song, "In the Street," by Alex Chilton and Chris Bell of the band Big Star. Beginning with the second season, the song was performed by the band Cheap Trick. The lyrics are as follows:
The same old thing, we did last week
Not a thing to do, but talk to you
We're all alright! We're all alright!
The final line ("We're all alright!") is inspired by the chorus to the Cheap Trick song "Surrender".
Danny Masterson, who plays Steven Hyde, yells "Hello, Wisconsin!" at the end of the theme song in the first season. In the first season, the lyrics were the same except that instead of shouting "We're all alright!" twice, they shout "Whoa yeah!"
- That '70s Show is one of the longest continuous running sitcoms for Fox in the US.
- The first working title for the Fox Network series was called Teenage Wasteland, before being changed to That '70s Show. Other names considered were The Kids Are Alright, Feelin' All Right, and Reeling in the Years.
- The show was remade by the British ITV network as Days Like These using almost verbatim scripts with minor changes to cultural references. The show failed to attract an audience and was removed from the schedules after 10 of the 13 episodes had been broadcast. The remaining three episodes were shown in a later run of repeats. Finally, the network just ran the original American version.