The ability to generate novel ideas, known as divergent thinking, is dependent on both semantic knowledge and episodic memory. Semantic knowledge and episodic memory are known to interact to support memory decisions, but it is not known how they may interact to support divergent thinking. We addressed this question by examining whether divergent thinking ability moderates interactions between semantic knowledge and different episodic memory processes in a spatial memory task. Participants completed the Alternative Uses Test to assess divergent thinking ability, then completed a memory task in which they searched for target objects that were either placed in semantically expected or semantically unexpected locations within scenes. In a subsequent test, participants indicated where in each scene the target object had been located previously (i.e., spatial accuracy test), then provided confidence-based recognition memory judgments that indexed distinct episodic memory processes (i.e., recollection, familiarity strength, and unconscious memory) for the scenes. We found that higher divergent thinking ability predicted 1) an increased benefit from putatively hippocampus-based episodic memory (i.e., recollection and unconscious memory) on spatial accuracy overall, and 2) beneficial differences in how semantic knowledge was combined with recollection and unconscious memory to influence spatial accuracy. In contrast, there were no effects of divergent thinking with respect to non-hippocampal memory (i.e., familiarity). These findings indicate that semantic knowledge and episodic memory function differently in highly divergent thinkers. In particular, these results suggest that divergent thinking is supported by the ability to flexibly combine semantic knowledge with episodic memory, particularly hippocampus-based memory.