Wirapol Sukphol, formerly Nen Kham, became notorious in 2013 when a YouTube video appeared to show him on a private jet with a designer bag and sunglasses.
Later in 2013 he was accused of having sex with an under-aged girl and fled to the US soon afterwards.
Mr Sukphol is expected strongly to contest all the charges against him.
He is reported to have resisted the move to extradite him from California.
The former monk faces charges of child molestation and child abduction. He is also charged with money laundering and fraud after investigators say millions of dollars of assets were discovered in his name.
He arrived on Wednesday in Bangkok wearing clerical garments despite being expelled from the monkhood, the Bangkok Post reported.
Buddhism is traditionally one of the three cornerstones of Thai society along with the nation and the monarchy. Temples are at the centre of community life, especially in rural areas.
But the monkhood has come under increased criticism in recent years following a succession of scandals, mostly involving sex and money.
The military - which has been running Thailand since a coup in 2014 - is under increasing pressure to tackle some of the alleged excesses.
One of the most high-profile cases has involved influential Buddhist abbot Phra Dhammajayo. He is wanted on money laundering charges but police were prevented from arresting him earlier this year by thousands of the abbot's supporters who say the charges are politically motivated.
A former monk has been charged with sex offences, fraud and money laundering after being extradited from the US to Thailand.