Gallagher (born Leo Anthony Gallagher on July 26, 1946 at Fort Bragg, North Carolina) is an American comedian and prop comic, most popularly known for smashing watermelons as part of his act.

His signature sketch is the “Sledge-O-Matic,” a large wooden mallet that Gallagher uses to smash a variety of objects, including computer keyboards, containers of cottage cheese, cartons of chocolate milk, tubes of toothpaste, pound cake ("I guess it does"), Big Macs, and, most famously, watermelons. Given the messy nature of this portion of his act, it is usually saved for the finale of his shows. Show attendees in the first two or three rows are usually provided with plastic sheeting for protection, and many fans bring their own additional protection (raincoats, umbrellas, and so on). Gallagher performs other prop-food gags including a demonstration of constipation using a jar of Jif peanut butter and an explanation of the difference between men and women using a sausage wrapped in a banana peel.

Gallagher claims he originally developed the sledge-o-matic act for George Carlin, but it was rejected so Gallagher used as the center piece of his own act.

In addition to the Sledge-O-Matic, Gallagher’s act features a variety of props, including a large trampoline designed to look like a couch, an adult sized Big Wheel, and a cap with a fringe of hair attached to the back.

In particular, while the Sledge-O-Matic act works as an example of physical prop comedy, Gallagher frequently uses this portion of his act as a criticism of American consumer culture. The act itself is a parody of ads for kitchen gadgets such as Ginsu knives that permeated the American television airwaves during non-primetime hours in the late 1970s. (See Wikiquotes for the traditional introduction to the Sledge-O-Matic sequence.)