Lester Louis Adler (born December 13, 1933) is an American record and film producer and the co-owner of the Roxy Theatre in West Hollywood, California. Adler has produced and developed a number of high-profile musical artists, including the Grass Roots, Jan & Dean, the Mamas & the Papas, and Carole King. King's album Tapestry, produced by Adler, won the 1972 Grammy Award for Album of the Year and has been called one of the greatest pop albums of all time.

Adler is an executive producer of The Rocky Horror Picture Show and discovered and produced comedy albums and films for Cheech & Chong. In 2006, he was awarded a star on the Hollywood Walk of Fame for his achievements in music. He was inducted into the Rock & Roll Hall of Fame in 2013 as the recipient, alongside Quincy Jones, of the Ahmet Ertegun Award.