The Old-fashioned glass is a short glass tumbler used for serving liquor "on the rocks" or over ice, or cocktails having few ingredients. It may be used to serve a wide variety of beverages over ice. The glass is named after the Old Fashioned cocktail traditionally served in such a glass, and is also known as rocks glass, Lowball or Whiskey glass.

The contemporary American Old-fashioned glass is usually able to hold between 6-8 oz.