Marc Brian Louis is a Singaporean athlete specialising in sprints and hurdles.

[2] Louis dabbled in football and swimming growing up, but eventually gravitated towards track and field.

[2] In 2019, Louis became the first Singaporean to win gold in the 400 m hurdles (55.09s) at the 2019 Asian Youth Athletics Championships held in Hong Kong.

[2] In 2021, while competing at the World Athletics U-20 Championships in Nairobi, Louis set a new national U-20 record for the 110 m hurdles with a time of 13.77s; he finished 11th overall.

[10] At the 2023 Southeast Asian Games in Phnom Penh, Louis won another bronze in the 4 x 100 m relay and a silver in the 100 m, matching his personal best of 10.39s in the latter.