King of the Royal Mounted (1940) is a Republic Pictures northern serial based on the King of the Royal Mounted comic strip directed by William Witney and John English.

Plot

In World War II, an unnamed enemy require a special mineral, Compound X, discovered in Canada. Although intended to cure paralysis, the enemy has discovered that it can be used in magnetic mines to destroy the British fleet and blockade America to prevent it assisting the Allies. The Mounties discover this plot and work to defeat and capture the spies sent to obtain the ore. Sgt King's father is killed in the line of duty, saving his son from death on a circular saw, and leaving him to carry on the fight against the enemy.