Schaefer Beer is a brand of American beer first produced in New York City during 1842 by the F. & M. Schaefer Brewing Company. The company relocated to Brooklyn in the early 20th century. It went public in 1968 with a $106 million stock offering.

In the mid-1970s, Schaefer Beer was one of the top selling beers in the U.S., ranking as high as fifth in both the 1950 and 1970 rankings.  Though it was producing more than twice as much beer in 1970 the gap between it and the top national brands was dramatically widening. Recognizing the handwriting on the wall, the Schaefer family sold out to the Stroh Brewery Company in 1981.

Stroh's then took over the Allentown plant in its own bid for national market share. It operated the plant until absorbed by Pabst Brewing Company in 1999. When Pabst opted to become a "virtual brewer" it sold the plant to Diageo just two years later. In 2008 Diageo sold it to the Boston Brewing Company, brewer of Samuel Adams beer.

Pabst retained the license to Schaefer and today outsources a reformulated brew it labels "Schaefer" and sells in niche markets in the United States.

The advertising slogan for Schaefer beer is the jingle "Schaefer is the one beer to have when you're having more than one." An earlier advertising campaign from the 1950s asserted, "What do you hear in the best of circles? Schaefer, all around!" In Spanish, Schaefer's slogan was "Es la mejor, cuando se toma mas de una!" (which translates to "It is the best, when you are having more than one!")

Schaefer beer had major exhibitions at both of New York City's World's Fairs, held in Flushing Meadows Park. During both the 1939 New York World's Fair and the 1964 New York World's Fair, Schaefer sponsored "Schaefer Center", a restaurant that used beer as an ingredient in many dishes.

Schaefer was the official beer sponsor of the Brooklyn Dodgers from 1951 until the franchise's departure for Los Angeles following the 1957 season. During that span, one of its advertisement was featured at the top of Ebbets Field's scoreboard on the right-field wall. The letters "h" and "e" on the wordmark lit up depending on whether the official scorer ruled that a batter reached base on a hit or an error respectively.

Foxboro Stadium, the home stadium of the New England Patriots from 1971-2001, was named originally named Schaefer Stadium after the beer company paid naming rights for the privilege, one of the earliest known examples of a stadium selling naming rights. After 12 years, the contract expired and the name was changed to Sullivan Stadium in 1983 (after the family that owned the team).