จักรภัทร แก้วพันธุ์พงษ์

William Jakrapatr Kaewpanpong is a quarter-American Thai singer, guitarist, pianist and main vocalist of the boy group LYKN signed under GMMTV and Riser Music. He was previously a vocalist and guitarist in the band Broccoli. Originally from Hat Yai, he graduated from Mahidol University's Young Artists Music Program before going on to study in Mahidol University's College of Music majoring in musical theatre and was a territorial defense student.

During the finale of "Project Alpha," William was crowned King of Alpha. Two months later, on May 5, 2023, LYKN's debut single "May I?" was released. His first solo single, "Last Twilight" was released on January 5, 2024.