The police ordered an investigation after a video showing a lion cub riding around the Thai resort town of Pattaya in a white Bentley gained more than 2.6 million views online.
Sawangjit Kosoognern was charged with breaking environmental and natural resources law by "possessing a protected wildlife without authorization", the Central Investigation Bureau announced on its official Facebook page.
"We have arrested her, using the Wild Animal Conservation and Protection Act 2019," the police statement said.
Under Thai law, she could be fined up to 100,000 baht (US$2,800) and face a year in jail.
Sawangjit told police she bought the lion from another woman for 250,000 baht but failed to acquire an official handover document due to insufficient information regarding the lion's sex.
She kept the young feline in a house rented by a Sri Lankan tourist who was seen driving the Bentley in the video.
He has been deported to Sri Lanka, the national parks and wildlife department said.