Kenneth Philip Grubb (September 14, 1895 – March 11, 1976) was a United States federal judge.
Born in Mauston, Wisconsin, Grubb was a U.S. Army Lieutenant in World War I, and thereafter received an LL.B. from the University of Wisconsin Law School in 1921. He was in private practice in Milwaukee, Wisconsin from 1921 to 1955.
Grubb was a federal judge on the United States District Court for the Eastern District of Wisconsin. Grubb was nominated by President Dwight D. Eisenhower on May 13, 1955, to a new seat created by 68 Stat. 8. He was confirmed by the United States Senate on June 15, 1955, and received his commission on June 16, 1955. Grubb served in that capacity until October 8, 1965, due to retirement.