Ronald Lee Nischwitz (born July 1, 1937) is a former Major League Baseball relief pitcher who played from 1961 to 1963, and again in 1965, for the Detroit Tigers and Cleveland Indians.

Before playing professional baseball, he attended Fairview High School and then Ohio State University.

Signed by the Tigers as an amateur free agent in 1958, Nischwitz made his big league debut on September 4, 1961, against the Baltimore Orioles.

In 642⁄3 innings, he struck out only 28 batters but proved to be a solid hitter, collecting five hits — including a triple — in 12 at-bats, for a .417 batting average.

Following his playing career, he served as the head coach of Dayton's Wright State University baseball team from 1975 to 2004.