Warning: This synopsis for the entire series is written with unmarked spoilers, and in chronological order to establish the backstories and motives of the Ghostface killers.
In the 1970s, an aspiring actress named Maureen Prescott attended a party held by director John Milton. At the party, she was raped by some of the male attendants, including Milton himself. She became pregnant and gave birth to a baby boy, who she put up for adoption. She quit her dreams and went on to the suburbs of Woodsboro and started a family of her own, with a daughter, Sidney Prescott, but the stress caused her to sleep around with men in Woodsboro. Decades later, in the 1990s, Roman Bridger, Maureen's son who spent his life seeking his biological mother, found Maureen in Woodsboro. Reminding her of her past, she rejected him. Obsessed with revenge, he filmed Maureen's many affairs, including one with the father of Billy Loomis, an avid horror fan who, coincidentally, was dating Sidney. Roman showed him the tape, and convinced Billy that this was the reason his mother left him. Roman also convinced Billy to kill Maureen with the help of accomplice, Stu Macher. The murder went ahead and they framed Cotton Weary, a man Sidney's mother was having an affair with.
Despite the murder revenge being complete, Billy and Stu would continue their murder spree, with Casey Becker and her boyfriend Steve Orth as their next victims. The murders continued, with Sidney being the center of attention and targeted with cruel pranks. Billy is arrested, but seemingly proven innocent when Ghostface calls Sidney, revealing that he (Ghostface) murdered her mother. School is postponed after Sidney is attacked in the bathroom, and the principal is murdered. Meanwhile, Gale Weathers, an investigative reporter seeking the truth about Maureen's death, teams up with police officer Dewey Riley, a friend of Sidney's. They join a party, with Sidney's friends Tatum (who is Dewey's sister) and Randy (a movie buff) also attending. Billy and Sidney have sex, Randy explains the conventions of a slasher film, and Tatum is killed. Shortly afterwards, Billy and Stu reveal themselves as the killers to Sidney and seemingly kill off Randy and Dewey. They reveal their plan to kill Sidney and frame her father for the murders, before they are both killed by her in self-defense. Randy and Dewey are shown to have survived.
About a year later when Sidney is attending college, a new horror franchise is released, called Stab, inspired by Billy and Stu's murder spree. Cotton Weary is proven innocent and released, and Sidney has a new boyfriend named Derek. Billy's mother was devastated by her son's death and sought to avenge him, so she met with a student named Mickey, who had his own plan to go on a murder spree and make scary movies the scapegoat. They begin killing students on campus in Ghostface costumes, like Billy and Stu before them, turning the campus into a media circus. Dewey arrives to check on Sidney, and Gale is back to help investigate this new murder spree. Cotton arrives wanting to talk to Sidney, but she is very stressed by this situation. Soon, Dewey and Gale become romantically attached and Randy is killed, for good this time. It is heavily implied Cotton is behind the murders, but then Sidney is caught alone as Mickey reveals himself as a killer, claiming Derek to be his accomplice. Derek is killed by Mickey and that's when Billy's mother reveals herself. She betrays Mickey and kills him. In the fight that follows, Cotton pulls a Big Damn Heroes and shoots Mrs. Loomis, before Sidney shoots her in the head to make sure she's dead. Sidney gives credit to Cotton being the hero, making up for testifying against him.
At the time of the third movie, a few years later, Cotton's fame earned him a talk show. Roman, jealous of his half-sister's fame and survival, makes a plan to murder her under the Ghostface mantle. He starts off by slicing and dicing Cotton and his girlfriend when he won't reveal Sidney's whereabouts. As it happens, Roman is now working for John Milton to make Stab 3, and Sidney has since become a crisis counselor for abused women living under an assumed name. Circumstances lead to Dewey, Gale, and Sidney being reunited on the set of Stab 3. Roman kills some of the cast and crew, terrorizing the main trio, and he fakes his death to throw them off the trail. Randy pulls off a cameo from beyond the grave, warning the gang about what to expect for the third film in a slasher series. Roman gets Sidney alone and reveals himself as the killer. He also explains everything to her, about Maureen, about how he was behind Billy's murder spree. Roman kills Milton and in the fight that follow, Sidney stabs Roman and he is shot in the head by Dewey. Dewey later proposes to Gale and Sidney eventually starts a career as a writer.
About a decade later, back in Woodsboro, Sidney's teenage cousin Jill has become jealous of Sidney's fame and wants it to herself. She convinces film buff Charlie Walker to be her accomplice on a new murder spree. Sidney returns to Woodsboro to promote her new book and Dewey and Gale have been long since married with Dewey as the new sheriff. The teens in Woodsboro are shown to be as proud of the first new murders as a horror fan would be, but Dewey thinks they aren't taking it seriously. Sidney and Gale join forces with some students of Woodsboro High to help investigate, while Dewey leads the police investigation. After a party held by the teens, Ghostface strikes again and Gale is injured, and Jill's mother is killed. Jill and her friends, and her ex boyfriend Robbie head regroup at Kirby's house. Jill and Charlie kill their friend Kirby(Although some fans say otherwise), but Sidney arrives in time to find out the truth. Jill admits her fame hungry nature and kills Charlie. She seemingly kills Sidney, and fakes her own injuries just as how Billy and Stu planned to in the original film. When at the hospital, Jill discovers Sidney is still alive and Dewey and Gale realize the truth. In the standoff that follows, Jill is shot and apparently killed, while the media praise her for being the new hero in these murders.