Theodore Bryant Comstock (1849–1915) was an American geologist, educator, university administrator, and mining consultant.

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

He earned a bachelor's degree at Pennsylvania State Agricultural College, and postgraduate degrees from Cornell University.

[2] 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.

[8] Theodore B. Comstock died at his home in Los Angeles on July 26, 1915.