Which classic cocktail is made with gin, vermouth, and an olive?

The classic cocktail made with gin, vermouth, and an olive is the Martini. The Martini is a renowned drink that emphasizes the balance between the botanicals in the gin and the herbal notes of vermouth. The addition of an olive often serves as both a garnish and a subtle flavor enhancer, contributing a briny element that complements the drink's overall profile.

While a Manhattan uses whiskey and sweet vermouth, and an Old Fashioned focuses on whiskey with sugar and bitters, neither of these involves gin or features an olive. The Margarita is a tequila-based cocktail, which further distinguishes it from the Martini. Hence, the Martini stands out as the quintessential cocktail made from the combination of gin, vermouth, and an olive, making it an iconic choice in the world of mixed drinks.