Perry Mason is an American legal drama series aired on CBS from September 21, 1957, to May 22, 1966. The title character, played by Raymond Burr, is a Los Angeles criminal defense lawyer who originally appeared in detective fiction by Erle Stanley Gardner. Many episodes were based on stories written by Gardner.

Perry Mason was one of Hollywood's first weekly one-hour series filmed for television, and remains one of the longest-running and most successful legal-themed television series. During its first season, it received a Primetime Emmy Award nomination for Outstanding Dramatic Series and it became one of the five most popular shows on television. Burr received two Emmy Awards for Outstanding Lead Actor in a Drama Series, and Barbara Hale received an Emmy Award for Outstanding Supporting Actress in a Drama Series for her portrayal of Mason's confidential secretary Della Street. Perry Mason and Burr were honored as Favorite Series and Favorite Male Performer in the first two TV Guide Award readers' polls. In 1960, the series received the first Silver Gavel Award presented for television drama by the American Bar Association.

Perry Mason has aired in syndication in the United States and internationally ever since its cancellation, and the complete series has been released on Region 1 DVD. A 2014 study found that Netflix users rate Raymond Burr as their favorite actor, with Barbara Hale number seven on the list.

The New Perry Mason, a 1973 revival of the series with a different cast, was poorly received and ran for 15 episodes. In 1985, Burr returned to play Mason in a successful series of Perry Mason television films airing on NBC. A total of 30 films were made; Burr starred in 26 of them before his death in 1993. Another series focusing on Perry Mason's origin story began airing in 2020 on HBO, with Matthew Rhys in the title role.

Perry Mason is a distinguished criminal-defense lawyer practicing in Los Angeles, California, most of whose clients have been wrongly charged with murder. He is ably assisted by his confidential secretary Della Street and by private investigator Paul Drake. The innocent suspect is usually prosecuted by district attorney Hamilton Burger, though the prosecution is handled by a local district attorney when the murder takes place outside Los Angeles County. In the early seasons, the police investigation is usually led by the homicide detective Lt. Arthur Tragg. (Later, other homicide detectives appear with increasing frequency.)

In a typical episode, the first half of the show introduces a client, who often hires Mason on non-murder related business, or becomes acquainted with him in some other way. The prospective murder victim and other important figures in the case are introduced, and then the client is wrongly accused of murder. Once the crime has been committed, while Tragg and Burger work to gather evidence against Mason's innocent client, Mason, Paul Drake and Della Street engage in a parallel investigation in order to exonerate him or her.

In the second half, Mason and Burger spar in the courtroom. This usually takes place during the preliminary hearing because Mason's technique is to clear a client before they are bound over for trial (based on novels). Jury trials are rarely seen, with "The Case of the Terrified Typist" being an exception. As the courtroom proceedings advance, while Burger and Tragg often uncover new evidence or a new witness that would seem to seal the fate of the accused, Mason's team continue their parallel investigation in what seems to be an increasingly hopeless effort. As the investigation or examination progresses, Mason and sometimes Burger uncover the morally ugly or even illegal conduct of some of the witnesses or participants, thus complicating the moral and legal intrigue of the case.

Eventually, some detail is uncovered, a different interpretation of the evidence is found, or a remark is made inside or outside the courtroom which gives Mason the clue he needs to discover the identity of the real murderer. (For example, in "The Case of the Lazy Lover", the prosecution's case relies on a complicated set of footprints left at the crime scene. Mason notices that the prints left by a neighbor's dog were inconsistent with Burger's interpretation, leading Mason to realize that the neighbor's testimony was contrary to the truth.) Armed with this new insight, Mason then usually embarks upon a line of questioning that reveals the surprise perpetrator, often causing them to break down and confess to the crime in the courtroom. In the closing scene or epilogue, Paul and Della, and sometimes Burger and Tragg, ask Mason what gave him the clue he needed; after Mason explains, he or someone else makes a humorous remark.