Roy W. Allen was an American entrepreneur who is best known for being a founder and namesake for A&W Root Beer and A&W Restaurants.

A&W Root Beer is an American brand of root beer that was founded in 1919 by Roy W. Allen and primarily available in the United States and Canada. Allen partnered with Frank Wright in 1922, creating the A&W brand and inspiring a chain of A&W Restaurants founded that year. Originally, A&W Root Beer sold for five cents.