Film memorabilia are objects considered of value because of their connection to the cinema. These include costumes, props, advertising posters, and scripts, among other things. Fans have always coveted memorabilia, but in recent years, what was once a hobby has mushroomed into big business, with millions of dollars changing hands in auctions held by such firms as Christie's and Sotheby's. In addition, many popular films have their collectible items sold via independent, online movie memorabilia stores, web auctions, and at film studio charity events.

In the early days, most people sought autographs or original photographs or posters. Collectors had to rely on a handful of news magazines that were full of various sellers offering mail order catalogues or asking to buy bulk lots, or particular items of interest. Occasionally, events would be organized which were structured around a live auction — these, while fewer in number today, still occur, and one can still buy memorabilia in person from trusted sellers on-site. The community was also fairly fragmented, with collectors and dealers spread out across the globe and no real consistent and reliable way to communicate with one another.

Movie studios were slow to recognize the value of their property, "generally viewing the material as junk taking up precious backlot real estate." Often, workers would just take souvenirs or sell items without permission, aware that their employers did not particularly care. One of the more notorious of these was costumer Kent Warner, who amassed a large private collection and made money selling to interested buyers. One of his friends claimed that Warner rescued Humphrey Bogart's Casablanca trench coat, which had been slated for burning.

The turning point came in 1970. Kirk Kerkorian had bought MGM the year before and installed James Thomas Aubrey, Jr. as president. As part of his cost-cutting measures, Aubrey decided to auction off hundreds of thousands of items. The success of this mammoth event made people take notice.

MGM sold the contents of seven sound stages "for a mere $1.5 million" to auctioneer David Weisz. There were over 350,000 costumes alone. Weisz hired Kent Warner to help catalog and prepare for the auction. In the course of his work, Warner found several pairs of the ruby slippers from The Wizard of Oz (it is common practice to make multiple copies of important props). One pair became the centerpiece of the event and sold for a then-unheard-of $15,000. Warner kept or sold an unknown number of other pairs.

Actress Debbie Reynolds spent $180,000 and "purchased thousands of items", the beginning of her large collection. Weisz "recouped eight times" what he paid "from eager nostalgia enthusiasts."

Among the items sold were:

The unsold items, "... truckloads of costume sketches, movie stills and other memorabilia were sent to the MGM Grand Hotel in Las Vegas to be sold in the gift shop and used as hotel decorations." The auction catalogs have now themselves become sought-after collectibles.