Jacob Weimer, nicknamed "Tornado Jake" (November 29, 1873 – June 19, 1928), was a starting pitcher in Major League Baseball who played for the Chicago Cubs (1903–1905), Cincinnati Reds (1906–1908) and New York Giants (1909). Weimer batted right-handed and threw left-handed. He was born in Ottumwa, Iowa. In a seven-season career, Weimer posted a 97–69 record with 657 strikeouts and a 2.23 ERA in 1472-2/3 innings pitched. Weimer emerged as one of the Chicago Cubs' top starting pitchers in the first part of 20th century. He went 21–9 with a 2.30 ERA in his 1903 rookie season and 20–14 with 1.91 in his sophomore year. After going 18–12 with 2.26 in 1905, he was sent to the Cincinnati Reds for third baseman Harry Steinfeldt and Jimmy Sebring before 1906. In a trade that benefited both teams, Steinfeld hit .327 to lead the Cubs to their first World Series and Weimer won 20 games for Cincinnati, but eventually faded and was sent to the New York Giants after two subpar seasons. He played his final game with the Giants in 1909. Weimer died in Chicago, at the age of 54.