The 1MDB scandal is one of the largest corruption cases in modern history, involving the alleged theft of billions of dollars from a Malaysian state fund co-founded by Najib Razak in 2009. US and Malaysian investigators estimate that at least US$4.5 billion was stolen from the fund, with about US$1 billion linked to Najib's accounts. The scandal triggered national outrage and contributed to the fall of his party, UMNO, in the 2018 elections. Najib, who served as prime minister from 2009 to 2018, was convicted in 2020 for graft and money laundering, becoming the first former Malaysian leader to be imprisoned.

The case has drawn international attention due to its scale and the involvement of high-ranking officials. Najib's conviction in 2020 was for the fraudulent diversion of 42 million ringgit from SRC International, a former unit of 1MDB. He began his prison term in August 2022 after his final appeal failed. The scandal has also led to broader anti-corruption efforts in Malaysia, including charges against other officials and a crackdown on military procurement corruption. The 1MDB case remains a defining issue in Malaysian politics, shaping public perception of the ruling elite and the fight against graft.