The Green Magician is a fantasy novella by American writers L. Sprague de Camp and Fletcher Pratt.

The fifth story in their Harold Shea series, it was first published in the November 1954 issue of the fantasy pulp magazine Beyond Fiction.

With professional assistance from the wizards of the Kalevala they succeeded in retrieving their friends, only to have Bayard inadvertently transport them to the world of Irish myth.

Aware that the local mores might force him to share his wife with their host, Harold attempts the return journey to their native universe, only to be stymied by Brodsky's unwillingness to go.

The fate of Walter Bayard remains a loose end, and is ultimately revealed in the later story "Sir Harold and the Gnome King."