Lance Corporal Mohamad Najib bin Haji Tarif is a Bruneian professional footballer who plays as a midfielder or defender for DPMM and the Brunei national team.

[4] Najib became the starting left-back for DPMM's 2017 campaign which ended in a disappointing 8th place, leading to the dismissal of coach Steve Kean.

[10] In 2022, DPMM competed domestically at the 2022 Brunei FA Cup, managing to advance to the final of the competition with Najib appearing regularly at the left side of the lineup.

[12] In the fifth minute of the Singapore Premier League fixture against Albirex Niigata (S) on 2 November 2024, Najib suffered a head injury that required medical assistance after a mid-air collision with an opposition player.

[18] Najib linked up with the Brunei national team for the two-legged 2018 AFF Suzuki Cup qualifying matches against Timor-Leste in early September 2018.

[20] He kept his place in a more advanced role on the return leg at Hassanal Bolkiah National Stadium a week later and scored the only goal of the game.

In June 2019, Najib was due to link up with the national team for the 2022 World Cup qualification matches against Mongolia, but pulled himself out of contention.