Minister Mentor was a position in the Cabinet of Singapore created in 2004 as part of a transition in political leadership.

The only person to hold the post, between 2004 and 2011, was Lee Kuan Yew.

On 12 August 2004, when Lee Hsien Loong succeeded Goh Chok Tong as the prime minister of Singapore, he announced the position of Minister Mentor, as part of a transition of political leadership, when naming his Cabinet.

Prior to Lee Kuan Yew's appointment as Minister Mentor, he was Senior Minister between 1990 and 2004 under Goh Chok Tong's Cabinet.

On 14 May 2011, following the general election that took place seven days earlier, Lee Kuan Yew and Goh Chok Tong announced their retirement from the Cabinet, but continued to serve as Members of Parliament (MPs) on the backbenches until Lee's death in 2015 and Goh's retirement from politics in 2020 respectively.