Weerayut Chansook, nicknamed Arm, is a Thai actor, singer, host, Youtuber, and model signed under GMMTV. He graduated from Srinakharinwirot University with a bachelor's degree in Fine Arts, majoring in Acting and Directing.

In 2007, he participated in the Luk Thung Star Contest where he placed as first runner-up. Later, he enrolled in a singing school. He debuted in the entertainment industry in 2010 as an artist under the record label RS Public Company Limited. With his singing and dancing abilities, he was selected as a member of Rookie BB, a boy band under the management of RS Music, along with Iang Sittha Sapanuchart and Pop Supasit Chinvinijkul.

Aside from singing, Weerayut has become known for his fashion and styling skills through his lifestyle program "Arm Share."