Roh Moo-hyun (Hangul: 노무현; Hanja: 盧武鉉; Korean pronunciation: [no mu hjʌn]) GOM (1 September 1946 – 23 May 2009) was the ninth President of the Republic of Korea (2003–2008). Roh's pre-presidential political career was focused on human rights advocacy for student activists in South Korea. His electoral career later expanded to a focus on overcoming regionalism in South Korean politics, culminating in his election to the presidency. He achieved a large following among younger internet users, particularly at the website OhMyNews, which aided his success in the presidential election.

Roh's election was notable for the arrival in power of a new generation of Korean politicians, the so-called 386 Generation, (i.e. people in their thirties when the term was coined, who had attended university in the 1980s, and who were born in the 1960s). This generation had been veterans of student protests against authoritarian rule, and advocated a conciliatory approach towards North Korea, even at the expense of good relations with the USA.

Despite high initial hopes, his presidency encountered strong opposition from the conservative Grand National Party and media. They constantly accused him of incompetence, and insulting criticism was frequently published in the media. As a result, many of Roh's policies, including a plan to move the capital, and a plan to form a coalition with the opposition, were also attacked and made no progress.

After leaving office, Roh returned to his hometown of Bongha Maeul. The constantly growing numbers of visits by his political supporters were seen as a threat to the Grand National Party. Fourteen months later, Roh was suspected of bribery by prosecutors, and the subsequent investigation attracted public attention. This scandal, the collapse of the "Pro-Roh faction" of politicians, the collapse of the Uri Party and the defeat of its successor the Democratic Party in the National Assembly, and the defeat of Roh's designated successor in the presidential elections, marked a decline in the political fortunes of the 386 Generation that had brought Roh to power.

Roh committed suicide on 23 May 2009 by jumping from a mountain cliff behind his home named "Bueong-i Bawi" (lit. "Owl's Rock"), after leaving a suicide note on his personal computer. About 4 million people have visited Roh's hometown named "Bongha Village" for a week after his death. His suicide was confirmed by police.