A tailgate party is a social event held on and around the open tailgate of a vehicle. Tailgating, which primarily takes place in the United States and Canada, often involves consuming alcoholic beverages while barbecuing and grilling food. Tailgate parties occur in the parking lots at stadiums and arenas, before and occasionally after games, festivals, and concerts. People attending such a party are said to be 'tailgating'. Many people participate even if their vehicles do not have tailgates. Tailgate parties also involve people bringing their own alcoholic beverages, barbecues, food, etcetera. which is sampled and shared among fans attending the tailgate. Tailgates are intended to be non-commercial events, so selling items to the fans is frowned upon and can even be considered illegal soliciting. Tailgating is often seen as a critical part of the sports experience in the United States. Because many American sports venues are surrounded by large parking lots, tailgating often takes place right outside stadium and arena entrances.

Tailgate parties have spread to the pre-game festivities at sporting events besides American football, such as basketball, hockey, baseball and soccer. They also occur at non-sporting events such as weddings, cultural festivals and concerts. As American football outside North America has copied many of its associated traditions from the National Football League (NFL) and college football, tailgating parties are also held at some American football games in Europe.