Marvin Rotblatt (born October 18, 1927 in Chicago, Illinois), nicknamed "Rotty", is a former left-handed pitcher in Major League Baseball for the Chicago White Sox in the 1948, 1950 and 1951 seasons. His ERAs in 1948 (7.85) and 1950 (6.23) were the highest in the majors. He failed to get a base hit in his career, leaving him with a batting average of .000. His minor league Southern Association record included a season-high 202 strikeouts and a no-hitter.
Before playing professional baseball, Rotblatt played for the University of Illinois at Urbana-Champaign. The 1947-48 team won the Big Nine Championship.
In 1964, students at Carleton College in Northfield, Minnesota named an intramural slow-pitch softball league after Rotblatt. Although traditional intramural softball is still played at Carleton, the name Rotblatt now refers to an annual beer softball game that is played with one inning for every year of the school's existence.