As a songwriter he has had over 100 songs recorded by various artists. In 1998 he won a Grammy Award for Record and Song of the year for producing and co-writing the song Sunny Came Home (a 1997 hit for Colvin). Albums he has produced have been nominated for a total of 14 Grammy Awards. In 2005 he composed the score for the film Winter Solstice. Leventhal produced and co-wrote all of the songs on Rosanne Cash's 2014 release, The River & the Thread. On 8 February 2015, The River & the Thread won 3 Grammy awards: Americana Album Of The Year, Best American Roots Song for A Feather's Not A Bird and Best American Roots Performance for A Feather's Not A Bird. John Leventhal's songs are represented by Downtown Music Publishing.
Leventhal lives with his wife Rosanne Cash and their children in New York City.