Katasila was born in Rasi Salai district, Sisaket province, in Isan.

He developed an interest in politics since a very young age, recalling the 1981 Thai military rebellion.

While a student at Kasetsart University, he had participated in Black May, a mass protest where people gathered to oust the junta government led by Suchinda Kraprayoon in 1992.

[1][2] In contemporary political history, Katasila is best known for being the coordinator of the People's Alliance for Democracy (PAD), or familiarly known as Yellow Shirts.

He was one of the co-founders and a candidate in the seventh list of MPs for the Action Coalition for Thailand Party, a political party founded by the leaders of the People's Democratic Reform Committee (PDRC).