Mansor bin Othman (Jawi: منصور بن عثمان) is a Malaysian politician who served as the Deputy Minister of Environment and Water in the Barisan Nasional (BN) administration under former Prime Minister Ismail Sabri Yaakob and former Minister Tuan Ibrahim from August 2021 to the collapse of the BN administration in November 2022, Deputy Minister of Higher Education in the Perikatan Nasional (PN) administration under former Prime Minister Muhyiddin Yassin and former Minister Noraini Ahmad from March 2020 to the collapse of the PN administration in August 2021, Member of Parliament (MP) for Nibong Tebal from May 2013 to November 2022, Deputy Chief Minister I of Penang, Member of the Penang State Executive Council (EXCO), Member of the Penang State Legislative Assembly (MLA) for Penanti from June 2009 to May 2018 as well as Chairman of the Defence and Home Affairs Select Committee from December 2018 to December 2019.

He served Anwar Ibrahim as political secretary after leaving his service as senior lecturer at University of Science Malaysia.

He was picked by PKR to contest the Penang State Legislative Assembly seat of Penanti in the 2009 by-election and won.

In the 2013 Malaysian general election, he was nominated to contest the parliamentary seat of Nibong Tebal and won.

On 21 October 2019, Othman collapsed while debating the 2020 Malaysian federal budget, later revealed to be the result of a reflex syncope.