Haunted Mouths

Kellin Quinn Bostwick (born April 24, 1986) is an American singer and musician. He is the lead vocalist and keyboardist of the rock band Sleeping with Sirens. He is known for his distinctive, high-pitched vocals and for collaborating with other artists, as well as the SEGA Sound Team on the game Sonic Frontiers (2022). Some of his best known collaborations are on the tracks "King for a Day" with Pierce the Veil, and "Love Race" with Machine Gun Kelly. In 2025, Quinn released A Collection of Greetings, his debut studio album under the solo project Haunted Mouths.