The Desert Inn (or the D.I.) was a hotel/casino built in 1950, located in Las Vegas, Nevada on Earth. In the holosuite program Bashir 62, a rendition of 1962, the Desert Inn was one of the biggest venues along the Vegas Strip.
Following the hostile takeover of Vic Fontaine's lounge by Frankie Eyes, Vic attempted to get gigs at other local casinos including the D.I., the Sands, the Dunes. None of them returned his calls. (DS9: "It's Only a Paper Moon")