His father is a director and his mother is a TV screenwriter. He began acting at the age of seven, in 1985, at the suggestion of his father, who, as the director, cast in the drama The Six Siblings . He next acted in the TV drama My Sweet Orange Tree, then stopped acting in order to attend school. He shortly studied for his bachelor's degree, at ABAC University, before he attended the Brooks Institute of Photography in California, USA. However, two years later, due to the 1997. Theeradej is currently one of Thailand's most popular actors. He gained immense popularity after his work in the series called Song Rao Nirun Dorn. All his projects from that point on, TV dramas, movies and even TV commercials, have become popular among Thais.
According to the Suan Dusit poll, Theeradej was voted the most popular Thai male star six years in a row from 2006 to 2011 and was honored the Most Popular Star Hall of Fame in 2012, along with Thongchai McIntyre & Pachrapa Chaichua.
He received the Golden Television Awards for Best Leading Actor a record four times for his work in Ey Mah Lek (2002), Song Rao Nirun Dorn (2005), Sawan Biang (2008) and Sood Sanaeha (2009).