Larry Dean McWilliams (born February 10, 1954) is an American former professional baseball pitcher, who played in Major League Baseball (MLB) for the Atlanta Braves (twice), Pittsburgh Pirates, St. Louis Cardinals, Philadelphia Phillies, and Kansas City Royals, from 1978-1990.

During his playing days, he stood 6 feet 5 inches (1.96 m) tall, weighing 180 pounds (82 kg).

On August 1, 1978, in what was just the fourth start of McWilliams’ first MLB campaign, he was the winning pitcher (raising his record to 4–0), when the Braves stopped Pete Rose's 44-game hitting streak at Atlanta-Fulton County Stadium.

[2] McWilliams made what was probably the key defensive play to stop the streak when, with two outs in the bottom of the second inning, Rose, in his second plate appearance of the game, lined a pitch up the middle that McWilliams reached back and caught.

On September 2, 1989, McWilliams was traded from the Philadelphia Phillies to the Kansas City Royals for Minor League Baseball (MiLB) catcher Jeff Hulse.