Mart Seim (born 24 October 1990) is an Estonian weightlifter competing in the +105 kg category.

Seim competed for Estonia at the 2014 World Weightlifting Championships finishing 4th with a total of 431 kg.

[1] At the 2015 World Weightlifting Championships he finished third at the men's +105 kg.

[2] After Aleksey Lovchev failed doping tests, Seim was promoted to second place (Silver), and Georgian Lasha Talakhadze to Gold.

[3] In August 2024, he finished in ninth place in the men's +102 kg event at the 2024 Summer Olympics held in Paris, France.