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 Magnum, who strongly prefers being called "private investigator" over "private eye", resides in a posh beach-front mansion owned by a professional writer, Mr. Robin Masters (a figure who is absent in the series although near the end of the show's career it was subtly implied that Higgins might be he). The lavish estate is managed by Higgins (full character name Jonathan Quayle Higgins III), an English gentleman and ex-British military intelligence officer and guarded by two highly trained Dobermann pinschers, Apollo & Zeus. 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-Navy buddies:

• Theodore "T.C." Calvin (who served with him in Vietnam - both often proudly display a 'Da Nang' baseball cap), conveniently a helicopter pilot who operates a tourist business "Island Hoppers"
• Rick, a suave playboy who also served in Vietnam can usually be found relaxing at the King Kamehameha Beach Club

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.