Magnum, P.I. was an American television show that followed the adventures of Thomas Magnum (played by Tom Selleck), a private investigator living in Hawaii. The show aired on the CBS network from 1980 to 1988.

Thomas Sullivan Magnum is a former U.S. Navy SEAL and Naval Intelligence officer who strongly prefers being called "private investigator" over "private eye" or "private detective." He resides in a posh beachfront mansion at the invitation of its owner, a professional writer, Mr. Robin Masters (a figure whose face is never actually seen) in exchange for his expertise in quality control of the estate's security. The lavish estate is managed by Higgins (full character name Jonathan Quayle Higgins III, played by John Hillerman), an English gentleman and ex-British military intelligence officer and guarded by two highly trained Dobermann pinschers, Apollo & Zeus. (Near the end of the series it was subtly implied that Higgins and Robin Masters might be one and the same person.)

Magnum's lifestyle represents every man's dream. He comes and goes as he pleases, drives a Ferrari 308 GTS, has a mini-fridge with a seemingly endless supply of beer, comes into contact with countless beautiful women (who are often his clients or victims in the cases he solves), and is joined by his two ex-military buddies, both former U.S. Marines and fellow members of the VM02 unit in Vietnam. All three wear a gold Team Ring, which bears a French croix on a black field, as a bond of wartime camaraderie. The buddies are:

• Theodore "T.C." Calvin (played by Roger E. Mosley ) (who - as does Magnum - often proudly displays a 'Da Nang' baseball cap), a helicopter pilot who operates a tourist charter business called "Island Hoppers." His combat-trained flight skills are often enlisted by Magnum during the course of an investigation.
• Orville "Rick" Wright (played by Larry Manetti ), a suave playboy who is manager of the King Kamehameha Club, an exclusive beachfront lounge. Rick also maintains a number of underworld contacts and is an expert in weaponry - he was T.C.'s door gunner during the war.

Magnum, P.I. is considered by many to be a perfect combination of action, comedy and drama. The show moved beyond the simple plot lines of the characters solving the crime of the week and confronted the difficulty Vietnam era soldiers faced in making the readjustment to civilian life. In fact Magnum is said to be one of the first shows to regularly explore the impact of the Vietnam War on the American cultural psyche.

There is also a movie in the works for 2005.

Magnum P.I.'s theme tune was one of many iconic TV themes written by Mike Post (Listen to the Theme of the Pilot here).

Trivia

One reason this show was set in Hawaii was so CBS could re-use many of the sets from its other hit show, Hawaii Five-O which had just completed its on-air run in 1980. Several early episodes make reference to the fictional Five-0 squad, setting this series in the same "universe" as Hawaii Five-O. Due to crossovers with other programs, the series is also shown to take place in the same continuity as Murder, She Wrote and Simon and Simon among others.

Magnum, P.I. is one of a small handful of dramas voted to have never "jumped the shark".