Marjorie Rees Clark (later Smith, born 6 November 1909, date of death unknown) was a South African former track and field athlete who competed in the 1928 Summer Olympics and in the 1932 Summer Olympics.
She was born in Bulwer, KwaZulu-Natal and competed for the Albion Ladies Athletic Club.
In 1928 she finished fifth in the Olympic high jump event. She also participated in the 100 metres competition but was eliminated in the semi-finals.
Four years later she won the bronze medal in the 80 metre hurdles contest at the 1932 Olympics. In the 1932 high jump event she finished fifth again and in the 100 metres competition but was eliminated in the first round.
At the 1934 Empire Games she won the gold medal in the 80 metre hurdles contest as well as in the high jump event. As a member of the South African relay team she finished fourth in the 110-220-110 yards competition. In the 100 yards contest and in the 220 yards event she was eliminated in the first round.