Cedric Bassett Popkin (20 June 1890 – 26 January 1968) was an Australian soldier considered most likely to have killed "The Red Baron".

Popkin was an anti-aircraft (AA) machine gunner with the First Australian Imperial Force (AIF) during the First World War.

At about 10:35 a.m. on 21 April, 1918, Richthofen, flying his red Fokker Dr.I, engaged Sopwith Camels from 209 Squadron, Royal Air Force (RAF).

One witness, Gunner George Ridgway, stated that when he and other Australian soldiers reached the plane, Richthofen was still alive but died moments later.

These facts, and the angle at which the bullet passed through Richthofen's body, suggest that he was killed by a long distance, low velocity shot from a ground-based weapon.

A memorial to Popkin is being planned for the hinterland town of Palmwoods by the local Returned and Services League (RSL) sub-branch.