Michael O'Brien was born in Memphis, Tennessee, in 1950. He graduated from the University of Tennessee, Knoxville, in 1972 with a B.A. in philosophy.
He began working as a staff photographer for the Miami News in 1973. In 1979, he moved to New York, where he worked as a freelance photographer for Life, National Geographic, Esquire, the New York Times Sunday Magazine, and others.
Currently he lives with his wife and three children in Austin, Texas. His clients include Texas Monthly, National Geographic, Reader's Digest, ESPN magazine, and dozens of others. O'Brien has won two Robert F. Kennedy Journalism Awards; his work is in the permanent collections of the Harry Ransom Center at the University of Texas in Austin, the Birmingham Museum of Art, the International Center of Photography in New York, the Museum of Fine Arts, Houston, The Tennessee State Museum, and the Wittliff Collection of Southwestern and Mexican Photography at Texas State University in San Marcos, Texas. In 2003, O'Brien published his first book, The Face of Texas, a collection of 80 portraits that celebrate the spirit and character of the state. The text was written by his wife, Elizabeth. O'Brien has photographed several feature stories for National Geographic, covering subjects such as coal mining, Australian portraits, river oaks, birding, and Austin, Texas.