Mary Danielle Lambert (born May 3, 1989) is a Seattle-based singer-songwriter and spoken word artist. She worked with Macklemore and Ryan Lewis on a track on their album The Heist. Lambert is the featured singer and songwriter of their gay rights single, "Same Love". Lambert wrote the chorus's hook in two hours. The "Same Love" chorus draws on Lambert's experiences as a lesbian growing up in a tumultuous, Christian upbringing. The repeating line, "Not crying on Sundays," for example, echoes the way she felt after leaving Sunday services in the Evangelical church. Lambert took the content she created for "Same Love" and used it to develop the song "She Keeps Me Warm" which she released on July 30, 2013. A music video was released on Vevo on August 24.

Lambert's songs, often emotionally charged, have been considered a mix of Adele, Tori Amos and James Blake. Her shows are described as "safe spaces where crying is acceptable and even encouraged." Her debut EP, Letters Don't Talk, was released on July 17, 2012, and peaked at number 18 on the iTunes Singer/Songwriter charts. On December 17, 2013, Lambert released her second EP, Welcome to the Age of My Body, under Capitol Records.