After graduating from Sungkyunkwan University, Lee worked as a public officer in the Economic Planning Board (current Ministry of Strategy and Finance) and later moved to the National Police Agency.

[1] On 23 January 2015, President Park Geun-hye named Lee, at the time parliamentary floor leader, as prime minister.

[6] On 20 April 2015, Lee offered to resign as Prime Minister, amid allegations of bribery.

[7][8] He formally stepped down on 27 April 2015, apologizing over a scandal in which he was accused of taking an illegal cash gift from Sung Wan-jong, a businessman.

[9] In January 2016, he was convicted of taking illegal funds by the Seoul Central District Court.