Student Patiwat Saraiyaem, 23, and activist Porntip Mankong, 26, pleaded guilty to defamation after their arrest last August, nearly a year after "The Wolf Bride", a satire set in a fictional kingdom, was performed at Bangkok's Thammasat University.
They were each charged with one count of lese majeste linked to the play, which marked the 40th anniversary of a pro-democracy student protest at the university that was brutally crushed by the military regime in October 1973.
Of those on the wanted list, at least two have fled Thailand, joining dozens of academics, activists and political opponents of the coup in self-exile amid a surge in royal defamation cases since the military seized power in May.
Thailand's King Bhumibol Adulyadej, 87, is revered by many in the country as a demi-god and shielded by one of the world's most draconian royal defamation laws.
Critics say the lese majeste law has been used as a tool to suppress political dissent, noting that many of those charged have been linked to the opposition Red Shirt movement.