Sineenat Wongvajirapakdi, 34, had been awarded the title of royal consort on July 28, the first woman to be ranked in nearly a century.
But an official announcement, released on Monday by the Thai royal household, stated that King Maha Vajiralongkorn had withdrawn all his royal titles and military lines for his "ambition" to be "equal to queen."
According to the notice, Sineenat had previously tried to prevent Queen Suthida Vajiralongkorn Na Ayudhya from being crowned and had asked to be appointed to the role instead.
"After her repeated violations and attempts to intervene in royal affairs, His Majesty the King granted her the title of Royal Noble Consort in July in the hope that Sineenat Wongvajirapakdi would reduce her pressure and change her behavior and actions," the statement said.
Sineenat "still exceeded its authority" and acted without the king's approval and against royal tradition, the statement said.
"Her actions are considered unfair, grateful, and unaware of His Majesty's kindness," message said. "They caused division between the royal servants and led to misunderstanding among the public. These constituted acts of sabotage against the country and the monarchy."
Under the King's order, Sineenat has now been removed from the official's position in the military and has had all insignia revoked.
Sineenat was a former Army nurse who served in the King's Royal Life Guard unit and held the military rank of Major General. She spent time in the military conducting jungle war and pilot training courses, according to state-run company Thai PBS.
Shortly after she became a consort, the Thai royal household released rare images of Sineenat and the king. In some pictures she is dressed in Thai formal attire sitting next to the king. In another, they hold both hands.
Before being crowned May in May, Vajiralongkorn had announced his marriage to General Suthida Vajiralongkorn Na Ayudhya, who had previously been his royal consort, and declared her queen. It was the fourth marriage of the king, who has two daughters and five sons, only one of whom is officially recognized as a prince.
Angie Puranasamriddhi contributed the reporting.