Quahog Clam Day is an annual event held in Quahog, Rhode Island. It is depicted as being very similar to a State Fair, having numerous sideshow attractions, games, and contests. The most recent was held in "Road to the Multiverse".

The fair is known for its Half-Man, Half-Clam, which Peter Griffin calls a ripoff upon the discovery that this side-show attraction is actually actress Kim Cattrall sitting Indian-style.

While most games seen at amusement parks and state fairs give away stuffed toys, the Quahog Clam Day fair gives away homosexual males, such as the one given to Chris Griffin.

At the "Guess Your Weight" station, a standard at state fairs and amusement parks, the worker guesses Mayor Adam West's weight wrong, prompting him to reveal he is composed of 95% helium, and floats away.