A cocktail glass is a narrow drinking glass having a stem and a wide, shallow, inverted cone fixed above it to hold liquid. The base of the stem is wide enough to maintain balance. The stem allows the user to hold the glass without permitting the heat from their hand to affect the temperature of the drink. This is particularly desirable for Martinis, which should remain cold whilst consumed.

A cocktail glass is often called a "martini glass" due to the popularity of that drink, which is served in a cocktail glass.