William Jakrapatr Kaewpanpong

Jakrapatr Kaewpanpong (Thai: จักรภัทร แก้วพันธุ์พงษ์; born 14 February 2005), nicknamed William (วิลเลี่ยม), is a Thai singer and actor. He is the main vocalist of the boy band LYKN under Riser Music and, since 2024, one half of an on screen partnership with Supha Sangaworawong, known as Est.

He grew up in Hat Yai, where he studied at Pholwitaya School and took up musical instruments and taekwondo, earning a black belt. Singing became his passion after he watched Tom Isara’s “Durian Mask” performance on The Mask Singer; he practised at home, then took formal vocal lessons, and later joined the Young Artist Music Program, a college preparatory programme of the College of Music at Mahidol University, majoring in musical theatre. In high school he sang with student bands including Lost & Found, Dolphin and Broccoli.

In 2022 he passed a remote audition for GMMTV’s survival show Project Alpha, recommended by the head of his school’s musical theatre department. The show ran from December 2022 to March 2023, and he held a top ranking “Alpha” position throughout before placing first overall in the finale, winning the title King of Alpha and a place as main vocalist of LYKN. The band, with Lego, Nut, Hong and Tui, debuted on 5 May 2023 with the digital single “May I?”. He also sang the solo theme “Last Twilight” for the 2023 series of the same name, which passed 30 million YouTube views by September 2026 and was nominated for Best Theme Song at the 29th Asian Television Awards.

His acting debut came in 2024 as Thame, Teema Kanjanakittkul, the leader of the fictional idol group MARS in ThamePo: Heart That Skips a Beat, opposite Est as the documentary director Po, with his LYKN bandmates in the cast. The series aired on GMM25 from 13 December 2024 to 7 March 2025, and he sang its solo track “5CM”. He then played Rome, Kritdanai Lee, the younger brother of the lead in Me and Thee (2025), with Est as Mok, a role both carried into Peach and Me. In You Maniac, which began on GMM25 on 29 August 2026, he leads as Dean, a party loving charmer who sets out to win over the artist Moth, played by Est, as a favour to a friend. In July 2025 he launched his own clothing brand, Zaven, and on 9 July 2026 he released the solo single “Flashback” with Riser Music.