William Timothy "Tim" O'Brien is an American novelist best known for his work of fiction, The Things They Carried, a critically acclaimed collection of semi-autobiographical, inter-related short-stories inspired by O'Brien's experiences in the Vietnam War. In addition, he is known for his work, Going After Cacciato, also written about wartime Vietnam.
O'Brien has held the endowed chair at the MFA program of Texas State University-San Marcos every other year since the 2003-2004 year.