Abraham Ezra Michelbacher (April 12, 1899 – May 22, 1991) was an American entomologist who served as a professor of entomology at the University of California, Berkeley.
Michelbacher was born in Riverside, California and grew up at Newport with an early interest in fishing which remained a recreation through his life.
He went to study agronomy at the Citrus Experiment Station which would later become the Riverside Campus from 1920 and here he was introduced to biological control by Harry Smith.
His career research was largely on applied entomology dealing with the management of insects in agriculture, particularly in alfalfa cultivation.
He also took an interest in the hymenopteran pollinators of cucurbits and gourds, making collection trips to South America.