Cornyn began working for Warner Bros. Records in 1958. He left the Warner Music Group in 1990 to live an office-free life. During his Warner years, he'd advanced to Executive VP of Warner Bros. Records; then to Senior VP of the Warner Music Group; and finally Founder and CEO of Warner New Media within Time-Warner. He is widely remembered for his years heading up Warner-Reprise's Creative Services department, writing innovative ads and other marketing approaches.

He was awarded the Grammy Award for Best Album Notes in 1966 for Frank Sinatra's Strangers in the Night and again in 1967 for Sinatra at the Sands. He was nominated in all for five Grammy Awards.

The literary qualities of his liner notes are discussed in A Storied Singer: Frank Sinatra as Literary Conceit in a chapter entitled "The Composition of Celebrity: Sinatra as Text in the Liner Notes of Stan Cornyn."

He co-authored the screenplay for Warner Bros.' 1970 film The Phynx.

In 1991 he was asked to lead the short-lived computer games division of Media Vision, Inc.

Cornyn is a graduate of Monrovia High School, Pomona College, attended Yale Graduate School, and received a Masters in Theatre from the University of California at Los Angeles in 1962.

Cornyn was twice married. First, in 1965, to the late Gail MacCrystall, by whom he fathered son Christopher Cornyn; then again, in 1971, to Theadora Davitt, by whom he has son Tom Cornyn.

Stan Cornyn currently resides in Carpinteria, California with longtime companion Meg Barbour, where Cornyn continues to write.

Stan is nephew to William Cornyn, previously the chair of both the Department of Slavic Languages and Literature and the Russian Area Program at Yale University; and John Cornyn II, father to U.S. Senator John Cornyn III (R. TX).