Sloe gin is a red liqueur made with gin and sloe (blackthorn) drupes, which are a small fruit relative of the plum. Sloe gin has an alcohol content between 15 and 30 percent by volume. However, the European Union has established a minimum of 25% ABV for sloe gin to be named as such. The traditional way of making sloe gin is to soak the sloes in gin. Sugar is required to ensure the sloe juice is extracted from the fruit.

Many commercial sloe gins today are made by flavouring less expensive neutral grain spirits, although some manufacturers still use the traditional method.