The man was initially detained in Bagan, an ancient town in central Myanmar where tourists flock to visit thousands of picturesque temples and pagodas.
"Monks in Bagan saw a Buddha tattoo on his right leg because he was wearing shorts. They informed us as it's not appropriate," a police officer in Bagan told AFP, requesting anonymity, adding that the Spaniard was promptly sent back to Yangon.
A police official at Yangon airport, who also asked not to be named, confirmed the detention and said the man would be deported to Bangkok on Monday evening.
"We will send him back because he violated the rules as a tourist here," he said.
Buddhist-majority Myanmar has seen a dramatic political transformation over recent years, with decades of junta rule giving way to a civilian-led government and a once isolated country opening up to lucrative foreign investment and tourists.
The changes have coincided with the rise of a small but influential Buddhist nationalist movement that rails against the five percent of the population that are Muslim and what are perceived to be corrupting Western
Portrayals of Buddha can land foreigners in hot water.
Last year a New Zealand bar manager spent 10 months in jail for "insulting religion" by using a Buddha image to promote a cheap drinks night.
A Canadian tourist and practising Buddhist was detained in 2014 for sporting a leg tattoo of Buddha.
Although many Buddhists, particular Western adherents, boast tattoos of the religion's founder, it can cause offence in some nations where the faith is practiced.
A British nurse was thrown out of Sri Lanka in 2014 for a Buddha tattoo on her arm despite her insistence she was a devotee who got inked as a mark of respect.
In Thailand, airports put up posters warning visitors not to get Buddha tattoos or buy statues.
Countries like Myanmar and Thailand believe the body becomes less sacred from the head down, making Buddha leg tattoos particularly problematic.