David Zellnik is the author of numerous plays and musicals seen in New York and beyond. 

His musicals - written with his brother,  composer Joseph Zellnik - include: book and lyrics for the Off-Broadway musical YANK! which received 7 Drama Desk nominations (including for his book and lyrics) as well as nominations from the Outer Critics’ Circle, and Lucille Lortel Foundation. The CD released by PS Classics and several regional productions are planned for the 2014/2015 season. His previous musical, CITY OF DREAMS has been performed in Cardiff, Wales at the first Int’l Music Theatre Festival, as well as in New York at the Midtown International Theatre Festival. David and Joe adapted the Arthur Giron play "Flight" for TheaterworksUSA, creating the musical FIRST IN FLIGHT which toured the country in 2004/5. Recently, David worked with Disney Theatricals to create PETER PAN JR (music: Eric Svejcar) which has been licensed and have several concurrent productions starting in 2013/2014. 

His plays include: ORVILLE AND WILBUR DID IT! at the New Colony in Chicago (2014); HUNTERS AND THIEVES (Blue Coyote Commission + first reading 2013); SERENDIB (The Hippodrome 2011; Off-Broadway Ensemble Studio Theatre 2008, created with a grant from the Alfred P. Sloan Foundation who sent him for 2 months to Sri Lanka to observe the scientists studying macaques in Polonnaruwa); ARIEL SHARON STANDS AT THE TEMPLE MOUNT AN DREAMS OF THEODOR HERZL (Epic Theatre Ensemble, Theatre J 2007); LET A HUNDRED FLOWERS BLOOM (Defunkt Theatre Co. Portland OR ‘14, New Ensemble ‘01 NYC OOBR Award) as well as the one-acts FOR ELISE, IDEOGRAM and KILLING HAND, all performed in various Ensemble Studio Theatre's Marathons. 

He has been given grants from the Sloan Foundation, NYSCA, Jerome Foundation and is a member of Ensemble Studio Theatre and as well as The Dramatists Guild and ASCAP.