Described by his friend Terence Knapp as "a lifelong enthusiast for all things Japanese," Earle Ernst became known for reviving Japanese theatre at the University of Hawai'i after World War II. While earning his AB degree from Gettysburg College (1933), he held a job playing piano for silent films. In 1940 he earned a PhD in Theater from Cornell University and was hired by the University of Hawai'i English Department to teach Shakespearean Comedy and other related subjects that same year.

Later, he served in the Army during World War II. While commissioned as second lieutenant in the Military Intelligence Service, he was assigned the Theater Censorship Section of the Civil Censorship Detachment (CCD) in General MacArthur's Occupation headquarters (1945-1947). In this role, Ernst was responsible for managing postwar censorship in an effort to reestablish the freedoms of performing traditional Japanese theatre, most notably kabuki, defined by its elaborate costuming, rhythmic dialogue, and men playing both male and female roles.

On Ernst's return to the states, he saw to it that a full kabuki stage was constructed at the University of Hawai'i in his continued effort to preserve the traditions of Japanese theatre. According to James R. Brandon, "He taught the first course on Asian theatre on any American campus. He was the first to stage English translations of Asian plays in 'authentic' performing style. He established at the University of Hawai'i the first PhD program in Asian theatre." Ernst translated and directed productions of kabuki, as well as modern, postwar Japanese dramas, and was "instrumental in bringing professional kabuki performances to Honolulu in 1964 and again in 1967."

Ernst wrote Finding Monju (2000), a novel published partially and posthumously and described by Japan Times writer Donald Richie as "a detailed description of occupied life in Tokyo 60 years ago, the everyday as well as the unusual." The novel is also unique in that it follows a gay protagonist and, according to Brandon, "is set among American soldiers stationed in war-ravaged Japan." Ernst was also the editor of Three Japanese Plays (1959) and wrote The Kubuki Theatre (1956), a work that provides an introductory history of kubuki and remains in print today.

Earl Ernst served as a Professor of Theatre Studies at the University of Hawai'i for 32 years, and students traveled from around the world to study with him. In retirement he enjoyed playing the piano for hours each day and gave up academic writings to work on his novel, Finding Monju. In 1994, Ernst died in Honolulu at the age of 82.