Theodore Bryant Comstock was born on July 27, 1849, in Cuyahoga Falls, Ohio.

He was an American explorer, geologist, mining engineer, and consultant. In 1886, he earned a Bachelor of Arts degree at Pennsylvania State Agricultural College. In 1870, he received a Bachelor of Science degree and a Doctor of Science degree in 1886 from Cornell University. He was a professor of general and economic geology at Cornell University from 1875 to 1879 and a professor of mining engineering and physics at the University of Illinois from 1885 to 1889. He was an Assistant State Geologist of Texas, Head of The University of Arizona School of Mines, and first president of The University of Arizona, 1894-1895. He made contributions to American Naturalist, the American Journal of Science, and the Engineering and Mining Journal.

In 1880, he married Blanche Huggins. He died on July 26, 1915, in Los Angeles, California.