William Earl Essick (December 18, 1880 – October 12, 1951), nicknamed "Vinegar Bill", was an American professional baseball pitcher in the Major Leagues.

He then became a longtime minor-league manager and team executive before joining the New York Yankees in 1935 as a scout.

A Look at Baseball's Scouts and Their Profession, Essick was credited with discovering or signing a number of Yankee future stars, including Joe DiMaggio, Lefty Gomez, Joe Gordon and Ralph Houk.

As a pitcher, Essick had a remarkable 1905 season in the Pacific Coast League for the Portland Beavers, throwing an astronomical 466.1 innings and ending up with a won-lost record of 23–30.

Sandoval wrote that Essick's nickname originated because the German word for vinegar is "Essig."