Quigley Down Under is a western film theatrically released in 1990. It was originally intended to star Steve McQueen in 1980, but after an illness by the star the project was suspended and not filmed until a decade later. Directed by Simon Wincer, the film runs 119 minutes, and is rated PG-13 in the United States.

Tom Selleck plays the titular Matthew Quigley, a cowboy and gunman from America with a keen eye and a specially modified rifle with which he can shoot at extraordinary distances. Quigley's weapon of choice is an 1874 Sharps Buffalo Rifle which fires .45-110 paper patch black powder cartridges. Its barrel is 34 inches long, which makes it four inches longer than an unmodified rifle. He answers an advertisement that asks for men with a special talent in long distance shooting, the job being in Australia. On arriving, he is met by employees of the man who hired him, Elliot Marston (Alan Rickman), and taken to Marston's ranch in the Australian Outback.

Marston is a gentleman infatuated with stories of quick-draw gunslingers from the American Old West, believing himself to have been born on the wrong continent, and amazed that Quigley has actually been to Dodge City. He hires Quigley to come to Australia in the hopes that Quigley will use his sharpshooting skills to help eradicate the native aborigines. Quigley finds the idea abhorrent and the two men are quickly headed for a showdown.

Laura San Giacomo provides comic relief and a love interest as "Crazy Cora." Having suffered a terrifying personal tragedy some years before the film's story begins, Cora appears to think that Quigley is her estranged husband, Roy. By the film's end, the viewer is left with some doubt as to how crazy she really is.

After Quigley turns Marston down, Marston has his men dump Quigley and Cora in the Australian Outback with no water and little chance of survival. Thanks to the possibly magical help of a group of aborigines, Quigley and Cora survive to rescue other aborigines from Marston's men, including an orphaned baby who helps Cora overcome her tragic past. As the story progresses, Marston loses more and more men to Quigley until the final showdown, which leaves Quigley standing to face a hostile British major. Again with the help of the aborigines, Quigley survives. The movie ends with Quigley and Cora purchasing passage on the next ship to America.

The film engendered a rapid rise in interest in the use of black powder, cartridge firing rifles for Metallic silhouette shooting competitions.

The famous firearm that is used by the main character Matthew Quigley is a custom 1874 Sharps Rifle. The gun used for filming was a replica manufactured for the film by the Shiloh Rifle Manufacturing Company of Big Timber, Montana. Tom Selleck later donated the rifle to the National Rifle Association as a fund-raising item.