Ould Mansour was a former President of the National Rally for Reform and Development party (Tewassoul) from 2007 to 2017.

He attended primary and secondary school in Nouakchott before going on to study at Mohammed V University in Morocco.

He was detained for several months, although was released before the 2003 presidential election, for which he supported former Head of State Mohamed Khouna Ould Haidalla.

[3][4][5] He was granted asylum from Belgium in 2003 due to the increasing clamp down by the Mauritanian Government on Islamist groups, however he returned to Mauritania in mid-2004.

[9][10] In August 2023, Mohamed Jemil Ould Mansour resigned and left the party Tewassoul.