Fourth Nattawat Jirochtikul is a Thai actor and singer. He was nicknamed Fourth as he was born on King Rama IV's 200th birthday. After getting his start in the company's "Thailand School Star 2019" contest, Fourth signed with GMMTV. He graduated from Saint Gabriel's College by taking the grade twelve equivalency test and is currently a student at Chulalongkorn University's Faculty of Law.

Fourth started in the entertainment industry in 2019 when he became one of the two winners of the GMMTV's star search competition "Thailand School Star 2019". In 2021, Fourth made his acting debut in the series "F4 Thailand: Boys Over Flowers". In May 2024, for his work on "Moonlight Chicken", he won the Outstanding Rising Star award at the Komchadluek Awards.

His first single, released in December 2022, was a collab cover of "Yak Rong Dang Dang" (อยากร้องดังดัง) as part of the soundtrack of the series "My School President", in which he played his debut lead role. His first original solo single came a couple months later with "Let Me Tell You" (พูดได้ไหม), another track for the series. After a number of releases with GMMTV Records, he became an artist under Riser Music in 2024. His first single under the label, "เทคะแนน (Candidate)" was released on February 20, 2024.

Aside his acting and singing career, Fourth owns the clothing brand 'NU MO NE'.