Yoon's quarterly approval rating fell to 24% this year, the lowest for a president's third year in office since Roh Moo-hyun's 23% in 2005-2006, according to Gallup Korea. Even Park Geun-hye, impeached and removed from office in 2017, managed 40% in her third year.
The embattled Yoon faces an impeachment vote on Saturday for imposing martial law late on Tuesday - only to rescind it six hours later when parliament unanimously rejected the measure.
Here are some of his previous controversies.
FIRST LADY
Yoon's wife, Kim Keon Hee, has been embroiled in myriad allegations, including accepting gifts such as a Christian Dior handbag from a pastor and manipulating stocks in Deutsch Motors, a BMW dealer in South Korea.
Last month Yoon said the allegations were false, accusing critics of "demonising my wife", although he apologised for causing public concern.
The unpopular first lady is cited as a major reason for Yoon's dismal ratings and a crushing defeat for his People Power Party in April.
Late last month Yoon vetoed a bill seeking a special council investigation into graft and stock manipulation allegations involving Kim, the third time he has rejected the opposition-led bill.
Yoon and Kim have been accused of meddling in the ruling party's candidate nomination process and of exerting influence on the party to pick a particular candidate to run for parliament in 2022 at the request of a power broker.
MARINE'S DEATH
Yoon vetoed a bill mandating a special counsel probe into allegations that military officials and the presidential office interfered in an investigation into the death of a young marine last year that prompted public outrage.
The marine was swept away while conducting a search and rescue operation for flood victims. He and his fellow marines did not have life jackets.
DOCTORS STRIKE
A months-long walkout by young doctors over Yoon's measures to address a doctor shortage strained South Korea's healthcare system and increased public criticism of the government's handling of the dispute.
HOT MIC
In 2022, Yoon was caught cursing on a hot mic after a meeting with U.S. President Joe Biden in New York.
Opposition lawmakers accused Yoon of insulting the U.S. Congress when media reported Yoon had said Biden would be embarrassed if it did not pass a bill on funding a health initiative. The presidential office denied the allegations, saying he was referring to the South Korean parliament.
OFFICE MOVE
After being elected in 2022, Yoon moved the presidential office from the Blue House to the defence ministry compound in central Seoul, a step estimated to cost $40 million, inviting criticism from the previous administration that the move was rushed and threatened national security.
Opposition lawmakers alleged Yoon had taken advice from a shaman about the move. He denied any influence, saying only that he knew the man as a Buddhist priest.
