The Thammasat University massacre took place during a period of heightened political tension in Thailand, where student protests were increasingly common due to dissatisfaction with the government. On October 6, right-wing paramilitaries, with the tacit support of the police, violently suppressed a student gathering aimed at expressing opposition to the return of former dictator Field Marshal Sarit Thanarat’s allies to power. As the situation escalated, hundreds of students were present at Thammasat University, which had become a hub for dissent against military rule. The police, armed with tear gas and live ammunition, engaged in a brutal crackdown that resulted in the deaths of dozens, although exact numbers remain disputed. Bodies were displayed in the streets, and many students faced severe violence as they sought refuge from the onslaught.

In the aftermath of the massacre, public outrage grew against the Seni Pramoj-led government, perceived as complicit or ineffective in preventing the violence. General Sangad Chaloryu mobilized military forces and staged a coup, successfully ousting the government, which marked a notable shift in Thailand's political dynamics. The new military leadership sought to restore order and eliminate political dissent, ushering in a period of increased repression against perceived leftist elements within the society. The events brought deep divisions within Thai society and continued unrest from student groups and other factions opposing military rule.