Martyn P. Casey is an Australian musician best known as the bassist for the alternative rock band Nick Cave and the Bad Seeds. He joined the band in 1990 and has contributed to many of their albums, showcasing his distinctive playing style and musical versatility. In addition to his work with Nick Cave and the Bad Seeds, Casey has collaborated with various artists and bands throughout his career. His contributions extend beyond bass playing, as he is also involved in songwriting and production, making him a respected figure in the Australian music scene.