Sarah Lewitinn (born February 3, 1980), also known by her nickname Ultragrrrl, is an American record producer, music critic, DJ, blogger, and music director for the Canadian fashion brand, Aritzia. She began her career as an assistant editor at Spin Magazine, and soon helped champion rock bands like My Chemical Romance and The Killers, which led to her starting her own record label, Stolen Transmission. In 2006, New York magazine named Lewitinn as one of the most "influential people in music", citing that "Like it or not, she has more power than any print music critic.".